refactor(core): replace all Union usage by | syntax in core except `core/vendor` [no changelog]

diff --git a/core/embed/upymod/modtrezorio/modtrezorio.c b/core/embed/upymod/modtrezorio/modtrezorio.c
index 9f605f14..08533ed5 100644
--- a/core/embed/upymod/modtrezorio/modtrezorio.c
+++ b/core/embed/upymod/modtrezorio/modtrezorio.c
@@ -88,7 +88,7 @@ uint32_t last_touch_sample_time = 0;
 
 /// USB_EVENT: int # interface id for USB events
 
-/// WireInterface = Union[USBIF, BLEIF]
+/// WireInterface = USBIF | BLEIF
 /// USBIF_WIRE: int  # interface id of the USB wire interface
 /// USBIF_DEBUG: int  # interface id of the USB debug interface
 /// USBIF_WEBAUTHN: int  # interface id of the USB WebAuthn
diff --git a/core/mocks/generated/trezorio/__init__.pyi b/core/mocks/generated/trezorio/__init__.pyi
index b14c2ee7..d26e1478 100644
--- a/core/mocks/generated/trezorio/__init__.pyi
+++ b/core/mocks/generated/trezorio/__init__.pyi
@@ -97,7 +97,7 @@ BUTTON_RELEASED: int  # button up event
 BUTTON_LEFT: int  # button number of left button
 BUTTON_RIGHT: int  # button number of right button
 USB_EVENT: int # interface id for USB events
-WireInterface = Union[USBIF, BLEIF]
+WireInterface = USBIF | BLEIF
 USBIF_WIRE: int  # interface id of the USB wire interface
 USBIF_DEBUG: int  # interface id of the USB debug interface
 USBIF_WEBAUTHN: int  # interface id of the USB WebAuthn
diff --git a/core/mocks/uio.pyi b/core/mocks/uio.pyi
index 808dc629..6cf1e651 100644
--- a/core/mocks/uio.pyi
+++ b/core/mocks/uio.pyi
@@ -6,10 +6,10 @@ class FileIO:
     def write(self, data: bytes | str) -> int: ...
 
 class StringIO:
-    def __init__(self, _: Union[int, str]) -> None: ...
+    def __init__(self, _: int | str) -> None: ...
 
 class BytesIO:
-    def __init__(self, _: Union[int, bytes]) -> None: ...
+    def __init__(self, _: int | bytes) -> None: ...
     def getvalue(self) -> bytes: ...
 
 def open(name: str, mode: str = ...) -> FileIO:
diff --git a/core/src/apps/cardano/helpers/chunks.py b/core/src/apps/cardano/helpers/chunks.py
index c63376b5..1ee81b09 100644
--- a/core/src/apps/cardano/helpers/chunks.py
+++ b/core/src/apps/cardano/helpers/chunks.py
@@ -6,12 +6,9 @@ from trezor.wire import ProcessError
 from trezor.wire.context import call as ctx_call
 
 if TYPE_CHECKING:
-    from typing import Generic, TypeVar, Union
+    from typing import Generic, TypeVar
 
-    Chunk = Union[
-        messages.CardanoTxInlineDatumChunk,
-        messages.CardanoTxReferenceScriptChunk,
-    ]
+    Chunk = messages.CardanoTxInlineDatumChunk | messages.CardanoTxReferenceScriptChunk
 
     C = TypeVar("C", bound=Chunk)
 else:
diff --git a/core/src/apps/monero/xmr/serialize/base_types.py b/core/src/apps/monero/xmr/serialize/base_types.py
index 8c9d8dc4..7ba850e4 100644
--- a/core/src/apps/monero/xmr/serialize/base_types.py
+++ b/core/src/apps/monero/xmr/serialize/base_types.py
@@ -1,17 +1,14 @@
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
-    from typing import Protocol, TypeVar, Union
+    from typing import Protocol, TypeVar
 
     T = TypeVar("T")
 
     XT = TypeVar("XT", bound="XmrType")
     ST = TypeVar("ST", bound="XmrStructuredType")
 
-    XmrFieldType = Union[
-        tuple[str, XT],
-        tuple[str, ST, XT],
-    ]
+    XmrFieldType = tuple[str, XT] | tuple[str, ST, XT]
 
     XmrFspec = tuple[XmrFieldType, ...]
 
diff --git a/core/src/trezor/loop.py b/core/src/trezor/loop.py
index 860c0207..fa680753 100644
--- a/core/src/trezor/loop.py
+++ b/core/src/trezor/loop.py
@@ -14,9 +14,11 @@ from typing import TYPE_CHECKING
 from trezor import io, log
 
 if TYPE_CHECKING:
-    from typing import Any, Awaitable, Callable, Coroutine, Generator, Union
+    from typing import Any, Awaitable, Callable, Coroutine, Generator
 
-    Task = Union[Coroutine, Generator, "wait"]
+    from .loop import wait
+
+    Task = Coroutine | Generator | wait
     AwaitableTask = Task | Awaitable
     Finalizer = Callable[[Task, Any], None]
 
diff --git a/core/tests/test_apps.ethereum.sign_typed_data.py b/core/tests/test_apps.ethereum.sign_typed_data.py
index 136170ad..3516f276 100644
--- a/core/tests/test_apps.ethereum.sign_typed_data.py
+++ b/core/tests/test_apps.ethereum.sign_typed_data.py
@@ -81,8 +81,7 @@ def get_field_type(type_name: str, types: dict) -> EFT:
 
     if is_array(type_name):
         data_type = EDT.ARRAY
-        array_size = parse_array_n(type_name)
-        size = None if array_size == "dynamic" else array_size
+        size = parse_array_n(type_name)
         member_typename = typeof_array(type_name)
         entry_type = get_field_type(member_typename, types)
     elif type_name.startswith("uint"):
@@ -138,10 +137,10 @@ def parse_type_n(type_name: str) -> int:
     raise ValueError(f"Invalid type name: {type_name}")
 
 
-def parse_array_n(type_name: str) -> Union[int, str]:
+def parse_array_n(type_name: str) -> int | None:
     """Parse N in type[<N>] where "type" can itself be an array type."""
     if type_name.endswith("[]"):
-        return "dynamic"
+        return None
 
     start_idx = type_name.rindex("[") + 1
     return int(type_name[start_idx:-1])