ci: remove Cirrus CI configuration

diff --git a/.cirrus.yml b/.cirrus.yml
deleted file mode 100644
index aef2e79..0000000
--- a/.cirrus.yml
+++ /dev/null
@@ -1,441 +0,0 @@
-# unittests using the 'latest' runtime python-dependencies
-task:
-  container:
-    image: $ELECTRUM_IMAGE
-    cpu: 1
-    memory: 2G
-  matrix:
-    - name: "unittests: py$ELECTRUM_PYTHON_VERSION"
-      env:
-        ELECTRUM_IMAGE: python:$ELECTRUM_PYTHON_VERSION
-      matrix:
-       - env:
-           ELECTRUM_PYTHON_VERSION: 3.10
-       - env:
-           ELECTRUM_PYTHON_VERSION: 3.11
-       - env:
-           ELECTRUM_PYTHON_VERSION: 3.12
-       - env:
-           ELECTRUM_PYTHON_VERSION: 3.13
-       - env:
-           ELECTRUM_PYTHON_VERSION: 3.14
-       - name: "unittests: py3.14, debug-mode"
-         env:
-           ELECTRUM_PYTHON_VERSION: 3.14
-           # enable additional checks:
-           PYTHONASYNCIODEBUG: "1"
-           PYTHONDEVMODE: "1"
-  pip_cache:
-    folder: ~/.cache/pip
-    fingerprint_script: echo $ELECTRUM_IMAGE && cat $ELECTRUM_REQUIREMENTS_CI && cat $ELECTRUM_REQUIREMENTS
-  tag_script:
-    - git tag
-  libsecp_build_cache:
-    folder: contrib/_saved_secp256k1_build
-    fingerprint_script: sha256sum ./contrib/make_libsecp256k1.sh
-    populate_script:
-      - apt-get update
-      - apt-get -y install automake libtool
-      - ./contrib/make_libsecp256k1.sh
-      - mkdir contrib/_saved_secp256k1_build
-      - cp electrum/libsecp256k1.so.* contrib/_saved_secp256k1_build/
-  install_script:
-    - apt-get update
-    # qml test reqs:
-    - apt-get -y install libgl1 libegl1 libxkbcommon0 libdbus-1-3
-    - pip install -r $ELECTRUM_REQUIREMENTS_CI
-    # electrum itself:
-    - export ELECTRUM_ECC_DONT_COMPILE=1
-    - pip install ".[tests,qml_gui]"
-  version_script:
-    - python3 --version
-    - pip freeze --all
-  pytest_script:
-    - >
-      coverage run --source=electrum \
-               "--omit=electrum/gui/*,electrum/plugins/*,electrum/scripts/*" \
-               -m pytest tests -v
-    - coverage report
-  coveralls_script:
-    - if [ ! -z "$COVERALLS_REPO_TOKEN" ] && [ "$ELECTRUM_PYTHON_VERSION" = "3.10" ] ; then coveralls ; fi
-  env:
-    LD_LIBRARY_PATH: contrib/_saved_secp256k1_build/
-    ELECTRUM_REQUIREMENTS_CI: contrib/requirements/requirements-ci.txt
-    ELECTRUM_REQUIREMENTS: contrib/requirements/requirements.txt
-    # following CI_* env vars are set up for coveralls
-    CI_NAME: "CirrusCI"
-    CI_BUILD_NUMBER: $CIRRUS_BUILD_ID
-    CI_JOB_ID: $CIRRUS_TASK_ID
-    CI_BUILD_URL: "https://cirrus-ci.com/task/$CIRRUS_TASK_ID"
-    CI_BRANCH: $CIRRUS_BRANCH
-    CI_PULL_REQUEST: $CIRRUS_PR
-    # in addition, COVERALLS_REPO_TOKEN is set as an "override" in https://cirrus-ci.com/settings/...
-  depends_on:
-    - "linter: Flake8 Mandatory"
-
-# unittests using the ~same frozen dependencies that are used in the released binaries
-# note: not using pinned pyqt here, due to "qml_gui" extra
-task:
-  container:
-    image: $ELECTRUM_IMAGE
-    cpu: 1
-    memory: 2G
-  name: "unittests: py3.10, frozen-deps"
-  pip_cache:
-    folder: ~/.cache/pip
-    fingerprint_script: echo $ELECTRUM_IMAGE && cat contrib/requirements/requirements*.txt && cat contrib/deterministic-build/requirements*.txt
-  tag_script:
-    - git tag
-  libsecp_build_cache:
-    folder: contrib/_saved_secp256k1_build
-    fingerprint_script: sha256sum ./contrib/make_libsecp256k1.sh
-    populate_script:
-      - apt-get update
-      - apt-get -y install automake libtool
-      - ./contrib/make_libsecp256k1.sh
-      - mkdir contrib/_saved_secp256k1_build
-      - cp electrum/libsecp256k1.so.* contrib/_saved_secp256k1_build/
-  install_script:
-    - apt-get update
-    # qml test reqs:
-    - apt-get -y install libgl1 libegl1 libxkbcommon0 libdbus-1-3
-    - pip install -r contrib/deterministic-build/requirements-build-base.txt
-    - pip install -r contrib/requirements/requirements-ci.txt
-    # electrum itself:
-    - export ELECTRUM_ECC_DONT_COMPILE=1
-    - pip install -r contrib/deterministic-build/requirements.txt -r contrib/deterministic-build/requirements-binaries.txt
-    - pip install ".[tests,qml_gui]"
-  version_script:
-    - python3 --version
-    - pip freeze --all
-  pytest_script:
-    - pytest tests -v
-  env:
-    ELECTRUM_IMAGE: python:3.10
-    LD_LIBRARY_PATH: contrib/_saved_secp256k1_build/
-  depends_on:
-    - "linter: Flake8 Mandatory"
-
-task:
-  name: "locale: upload to crowdin"
-  container:
-    image: $ELECTRUM_IMAGE
-    cpu: 1
-    memory: 1G
-  pip_cache:
-    folder: ~/.cache/pip
-    fingerprint_script: echo Locale && echo $ELECTRUM_IMAGE && cat $ELECTRUM_REQUIREMENTS_CI
-  install_script:
-    - apt-get update
-    - apt-get -y install gettext qt6-l10n-tools
-    - pip install -r $ELECTRUM_REQUIREMENTS_CI
-    - pip install requests
-  submodules_script:
-    - git submodule update --init
-  locale_script:
-    - contrib/locale/push_locale.py
-  env:
-    ELECTRUM_IMAGE: python:3.10
-    ELECTRUM_REQUIREMENTS_CI: contrib/requirements/requirements-ci.txt
-    # in addition, crowdin_api_key is set as an "override" in https://cirrus-ci.com/settings/...
-    #   - api key is for crowdin account: "SomberNight_CI_BOT"
-    #   - see https://crowdin.com/settings#api-key
-  depends_on:
-    - "unittests: py3.10"
-  only_if: $CIRRUS_BRANCH == 'master'
-
-task:
-  name: "Regtest functional tests"
-  compute_engine_instance:
-    image_project: cirrus-images
-    image: family/docker-builder
-    platform: linux
-    cpu: 1
-    memory: 1G
-  pip_cache:
-    folder: ~/.cache/pip
-    fingerprint_script: echo Regtest && echo docker_builder && cat $ELECTRUM_REQUIREMENTS
-  bitcoind_cache:
-    folder: /tmp/bitcoind
-    populate_script: mkdir -p /tmp/bitcoind
-  install_script:
-    - apt-get update
-    - apt-get -y install curl jq bc
-    - python3 -m pip install --user --upgrade pip
-    # install electrum
-    - export ELECTRUM_ECC_DONT_COMPILE=1  # we build manually to make caching it easier
-    - python3 -m pip install .[tests] --ignore-installed  # ignore installed system installed attrs
-    # install e-x some commits after 1.18.0 tag
-    - python3 -m pip install git+https://github.com/spesmilo/electrumx.git@0b260d4345242cc41e316e97d7de10ae472fd172
-    - "BITCOIND_VERSION=$(curl https://bitcoincore.org/en/download/ | grep -E -i --only-matching 'Latest version: [0-9\\.]+' | grep -E --only-matching '[0-9\\.]+')"
-    - BITCOIND_FILENAME=bitcoin-$BITCOIND_VERSION-x86_64-linux-gnu.tar.gz
-    - BITCOIND_PATH=/tmp/bitcoind/$BITCOIND_FILENAME
-    - BITCOIND_URL=https://bitcoincore.org/bin/bitcoin-core-$BITCOIND_VERSION/$BITCOIND_FILENAME
-    - tar -xaf $BITCOIND_PATH || (rm -f /tmp/bitcoind/* && curl --output $BITCOIND_PATH $BITCOIND_URL && tar -xaf $BITCOIND_PATH)
-    - cp -a bitcoin-$BITCOIND_VERSION/* /usr/
-  libsecp_build_cache:
-    folder: contrib/_saved_secp256k1_build
-    fingerprint_script: sha256sum ./contrib/make_libsecp256k1.sh
-    populate_script:
-      - apt-get -y install automake libtool
-      - ./contrib/make_libsecp256k1.sh
-      - mkdir contrib/_saved_secp256k1_build
-      - cp electrum/libsecp256k1.so.* contrib/_saved_secp256k1_build/
-  bitcoind_service_background_script:
-    - tests/regtest/run_bitcoind.sh
-  electrumx_service_background_script:
-    - tests/regtest/run_electrumx.sh
-  # if any test fails, the test will get aborted (--failfast) and the wallet directories will be
-  # available for download in the Cirrus UI
-  regtest_script:
-    - sleep 10s
-    - python3 -m unittest tests/regtest.py --failfast || TEST_EXIT_CODE=$?
-    - tar -czf test_wallets.tar.gz /tmp/alice /tmp/bob /tmp/carol || true
-    - exit ${TEST_EXIT_CODE:-0}
-  on_failure:
-    wallet_artifacts:
-      path: "test_wallets.tar.gz"
-  env:
-    LD_LIBRARY_PATH: contrib/_saved_secp256k1_build/
-    ELECTRUM_REQUIREMENTS: contrib/requirements/requirements.txt
-    PIP_BREAK_SYSTEM_PACKAGES: 1
-    # ElectrumX exits with an error without this:
-    ALLOW_ROOT: 1
-  depends_on:
-    - "linter: Flake8 Mandatory"
-
-task:
-  container:
-    image: $ELECTRUM_IMAGE
-    cpu: 1
-    memory: 1G
-  pip_cache:
-    folder: ~/.cache/pip
-    fingerprint_script: echo Flake8 && echo $ELECTRUM_IMAGE && cat $ELECTRUM_REQUIREMENTS
-  install_script:
-    - pip install "flake8==7.3.0" "flake8-bugbear==25.10.21"
-  flake8_script:
-    - flake8 . --count --select="$ELECTRUM_LINTERS" --ignore="$ELECTRUM_LINTERS_IGNORE" --show-source --statistics --exclude "*_pb2.py,electrum/_vendor/"
-  env:
-    ELECTRUM_IMAGE: python:3.10
-    ELECTRUM_REQUIREMENTS: contrib/requirements/requirements.txt
-  matrix:
-    - name: "linter: Flake8 Mandatory"
-      env:
-        # list of error codes:
-        # - https://flake8.pycqa.org/en/latest/user/error-codes.html
-        # - https://pycodestyle.pycqa.org/en/latest/intro.html#error-codes
-        # - https://github.com/PyCQA/flake8-bugbear/tree/8c0e7eb04217494d48d0ab093bf5b31db0921989#list-of-warnings
-        ELECTRUM_LINTERS: E9,E101,E129,E273,E274,E703,E71,E722,F5,F6,F7,F8,W191,W29,B,B909
-        ELECTRUM_LINTERS_IGNORE: B007,B009,B010,B036,B042,F541,F841
-    - name: "linter: Flake8 Non-Mandatory"
-      env:
-        ELECTRUM_LINTERS: E,F,W,C90,B
-        ELECTRUM_LINTERS_IGNORE: ""
-      allow_failures: true
-
-task:
-  name: "linter: ban unicode"
-  container:
-    image: python:3.10
-    cpu: 1
-    memory: 1G
-  main_script:
-    - contrib/ban_unicode.py
-
-task:
-  name: "security review: Claude Code"
-  # NOTE: claude has access to all API keys available in the Cirrus CI environment.
-  # If we would add some critical api keys in here we should consider this.
-  matrix:
-    - trigger_type: automatic
-      only_if: $CIRRUS_PR != '' && ($CIRRUS_USER_PERMISSION == 'write' || $CIRRUS_USER_PERMISSION == 'admin')
-    - trigger_type: manual
-      only_if: $CIRRUS_PR != '' && !($CIRRUS_USER_PERMISSION == 'write' || $CIRRUS_USER_PERMISSION == 'admin')
-  container:
-    image: node:20
-    cpu: 1
-    memory: 2G
-  # CLAUDE_CODE_OAUTH_TOKEN is set as an encrypted "override" in https://cirrus-ci.com/settings/...
-  # It must be stored encrypted (ENCRYPTED[...]) so Cirrus CI refuses to decrypt it for
-  # fork PRs from users without write permission.
-  # Generate with: claude setup-token
-  # Optional: set GITHUB_TOKEN to enable PR comments on failure
-  install_script:
-    - npm install -g @anthropic-ai/claude-code
-  review_script:
-    # the script is executed as 'node' user as claude refuses to run with root permissions
-    - chown -R node:node .
-    - su node -c "python3 contrib/ci/claude_security_review.py"
-
-# Cron jobs configured in https://cirrus-ci.com/settings/...
-# - job "nightly" on branch "master" at "0 30 2 * * ?"  (every day at 02:30Z)
-task:
-  name: "build: Windows"
-  matrix:
-    - trigger_type: manual
-      only_if: $CIRRUS_CRON == ""
-    - trigger_type: automatic
-      only_if: $CIRRUS_CRON == "nightly"
-  container:
-    dockerfile: contrib/build-wine/Dockerfile
-    cpu: 1
-    memory: 3G
-  pip_cache:
-    folders:
-      - contrib/build-wine/.cache/win*/wine_pip_cache
-    fingerprint_script:
-      - echo $CIRRUS_TASK_NAME
-      - git ls-files -s contrib/deterministic-build/*.txt
-      - git ls-files -s contrib/build-wine/
-  build2_cache:
-    folders:
-      - contrib/build-wine/.cache/win*/build
-    fingerprint_script:
-      - echo $CIRRUS_TASK_NAME
-      - cat contrib/make_libsecp256k1.sh | sha256sum
-      - cat contrib/make_libusb.sh | sha256sum
-      - cat contrib/make_zbar.sh | sha256sum
-      - git ls-files -s contrib/build-wine/
-  build_script:
-    - cd contrib/build-wine
-    - ./make_win.sh
-  binaries_artifacts:
-    path: "contrib/build-wine/dist/*"
-  env:
-    CIRRUS_WORKING_DIR: /opt/wine64/drive_c/electrum
-    CIRRUS_DOCKER_CONTEXT: contrib/build-wine
-  depends_on:
-    - "unittests: py3.10"
-
-task:
-  name: "build: Android (QML $APK_ARCH)"
-  matrix:
-    - trigger_type: manual
-      only_if: $CIRRUS_CRON == ""
-    - trigger_type: automatic
-      only_if: $CIRRUS_CRON == "nightly"
-  timeout_in: 90m
-  container:
-    dockerfile: contrib/android/Dockerfile
-    cpu: 8
-    memory: 24G
-  env:
-    APK_ARCH: arm64-v8a
-  packages_tld_folder_cache:
-    folder: packages
-    fingerprint_script:
-      - echo $CIRRUS_TASK_NAME && cat contrib/deterministic-build/requirements.txt && cat contrib/make_packages.sh
-      - git ls-files -s contrib/android/
-  p4a_cache:
-    folders:
-      - ".buildozer/android/platform/build-$APK_ARCH/packages"
-      - ".buildozer/android/platform/build-$APK_ARCH/build"
-    fingerprint_script:
-      # note: should *at least* depend on Dockerfile and p4a_recipes/, but contrib/android/ is simplest
-      - git ls-files -s contrib/android/
-      - echo "qml $APK_ARCH"
-  build_script:
-    - ./contrib/android/make_apk.sh qml "$APK_ARCH" debug
-  binaries_artifacts:
-    path: "dist/*"
-  depends_on:
-    - "unittests: py3.10"
-
-## mac build disabled, as Cirrus CI no longer supports Intel-based mac builds
-#task:
-#  name: "build: macOS"
-#  macos_instance:
-#    image: catalina-xcode-11.3.1
-#  env:
-#    TARGET_OS: macOS
-#  pip_cache:
-#    folder: ~/Library/Caches/pip
-#    fingerprint_script:
-#      - echo $CIRRUS_TASK_NAME
-#      - git ls-files -s contrib/deterministic-build/*.txt
-#      - git ls-files -s contrib/osx/
-#  build2_cache:
-#    folder: contrib/osx/.cache
-#    fingerprint_script:
-#      - echo $CIRRUS_TASK_NAME
-#      - cat contrib/make_libsecp256k1.sh | shasum -a 256
-#      - cat contrib/make_libusb.sh | shasum -a 256
-#      - cat contrib/make_zbar.sh | shasum -a 256
-#      - git ls-files -s contrib/osx/
-#  install_script:
-#    - git fetch --all --tags
-#  build_script:
-#    - ./contrib/osx/make_osx.sh
-#  sum_script:
-#    - ls -lah dist
-#    - shasum -a 256 dist/*.dmg
-#  binaries_artifacts:
-#    path: "dist/*"
-
-task:
-  name: "build: AppImage"
-  matrix:
-    - trigger_type: manual
-      only_if: $CIRRUS_CRON == ""
-    - trigger_type: automatic
-      only_if: $CIRRUS_CRON == "nightly"
-  compute_engine_instance:
-    image_project: cirrus-images
-    image: family/docker-builder
-    platform: linux
-    cpu: 2
-    memory: 2G
-  pip_cache:
-    folder: contrib/build-linux/appimage/.cache/pip_cache
-    fingerprint_script:
-      - echo $CIRRUS_TASK_NAME
-      - git ls-files -s contrib/deterministic-build/*.txt
-      - git ls-files -s contrib/build-linux/appimage/
-  build2_cache:
-    folder: contrib/build-linux/appimage/.cache/appimage
-    fingerprint_script:
-      - echo $CIRRUS_TASK_NAME
-      - cat contrib/make_libsecp256k1.sh | sha256sum
-      - git ls-files -s contrib/build-linux/appimage/
-  build_script:
-    - ./contrib/build-linux/appimage/build.sh
-  binaries_artifacts:
-    path: "dist/*"
-  depends_on:
-    - "unittests: py3.10"
-
-task:
-  container:
-    dockerfile: contrib/build-linux/sdist/Dockerfile
-    cpu: 1
-    memory: 1G
-  pip_cache:
-    folder: ~/.cache/pip
-    fingerprint_script:
-      - echo $CIRRUS_TASK_NAME
-      - git ls-files -s contrib/deterministic-build/*.txt
-      - git ls-files -s contrib/build-linux/sdist/
-  build_script:
-    - ./contrib/build-linux/sdist/make_sdist.sh
-  binaries_artifacts:
-    path: "dist/*"
-  matrix:
-    - name: "build: tarball"
-    - name: "build: source-only tarball"
-      env:
-        OMIT_UNCLEAN_FILES: 1
-  depends_on:
-    - "unittests: py3.10"
-
-task:
-  name: "check submodules"
-  container:
-    image: python:3.10
-    cpu: 1
-    memory: 1G
-  fetch_script:
-    - git fetch --all --tags
-  check_script:
-    - ./contrib/deterministic-build/check_submodules.sh
-  only_if: $CIRRUS_TAG != ''
diff --git a/contrib/build_tools_util.sh b/contrib/build_tools_util.sh
index 2dd9b8b..1e8d9c2 100755
--- a/contrib/build_tools_util.sh
+++ b/contrib/build_tools_util.sh
@@ -172,12 +172,7 @@ fi
 
 export GCC_STRIP_BINARIES="${GCC_STRIP_BINARIES:-0}"
 
-if [ -n "$CIRRUS_CPU" ] ; then
-    # special-case for CI. see https://github.com/cirruslabs/cirrus-ci-docs/issues/1115
-    export CPU_COUNT="$CIRRUS_CPU"
-else
-    export CPU_COUNT="$(nproc 2> /dev/null || sysctl -n hw.ncpu)"
-fi
+export CPU_COUNT="$(nproc 2> /dev/null || sysctl -n hw.ncpu)"
 info "Found $CPU_COUNT CPUs, which we might use for building."