Add `rust-version` to all crates' `Cargo.toml`s

diff --git a/lightning-background-processor/Cargo.toml b/lightning-background-processor/Cargo.toml
index 415676f..44edb97 100644
--- a/lightning-background-processor/Cargo.toml
+++ b/lightning-background-processor/Cargo.toml
@@ -8,6 +8,7 @@ description = """
 Utilities to perform required background tasks for Rust Lightning.
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/lightning-block-sync/Cargo.toml b/lightning-block-sync/Cargo.toml
index b001b47..2b42e3c 100644
--- a/lightning-block-sync/Cargo.toml
+++ b/lightning-block-sync/Cargo.toml
@@ -8,6 +8,7 @@ description = """
 Utilities to fetch the chain data from a block source and feed them into Rust Lightning.
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/lightning-custom-message/Cargo.toml b/lightning-custom-message/Cargo.toml
index fd0d302..202edc6 100644
--- a/lightning-custom-message/Cargo.toml
+++ b/lightning-custom-message/Cargo.toml
@@ -8,6 +8,7 @@ description = """
 Utilities for supporting custom peer-to-peer messages in LDK.
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/lightning-dns-resolver/Cargo.toml b/lightning-dns-resolver/Cargo.toml
index 19ffe44..3a3c5f3 100644
--- a/lightning-dns-resolver/Cargo.toml
+++ b/lightning-dns-resolver/Cargo.toml
@@ -6,6 +6,7 @@ license = "MIT OR Apache-2.0"
 repository = "https://github.com/lightningdevkit/rust-lightning/"
 description = "A crate which implements DNSSEC resolution for lightning clients over bLIP 32 using `tokio` and the `dnssec-prover` crate."
 edition = "2021"
+rust-version = "1.75"
 
 [dependencies]
 lightning = { version = "0.2.0", path = "../lightning", default-features = false }
diff --git a/lightning-invoice/Cargo.toml b/lightning-invoice/Cargo.toml
index 8e0c758..46b62ed 100644
--- a/lightning-invoice/Cargo.toml
+++ b/lightning-invoice/Cargo.toml
@@ -9,6 +9,7 @@ keywords = [ "lightning", "bitcoin", "invoice", "BOLT11" ]
 readme = "README.md"
 repository = "https://github.com/lightningdevkit/rust-lightning/"
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/lightning-liquidity/Cargo.toml b/lightning-liquidity/Cargo.toml
index a29fc36..3def079 100644
--- a/lightning-liquidity/Cargo.toml
+++ b/lightning-liquidity/Cargo.toml
@@ -5,6 +5,7 @@ authors = ["John Cantrell <johncantrell97@gmail.com>", "Elias Rohrer <dev@tnull.
 homepage = "https://lightningdevkit.org/"
 license = "MIT OR Apache-2.0"
 edition = "2021"
+rust-version = "1.75"
 description = "Types and primitives to integrate a spec-compliant LSP with an LDK-based node."
 repository = "https://github.com/lightningdevkit/lightning-liquidity/"
 readme = "README.md"
diff --git a/lightning-macros/Cargo.toml b/lightning-macros/Cargo.toml
index abeca85..8a20670 100644
--- a/lightning-macros/Cargo.toml
+++ b/lightning-macros/Cargo.toml
@@ -8,6 +8,7 @@ description = """
 Proc macros used by LDK
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 rustdoc-args = ["--cfg", "docsrs"]
diff --git a/lightning-net-tokio/Cargo.toml b/lightning-net-tokio/Cargo.toml
index 3fde86c..d5b6df5 100644
--- a/lightning-net-tokio/Cargo.toml
+++ b/lightning-net-tokio/Cargo.toml
@@ -9,6 +9,7 @@ Implementation of the rust-lightning network stack using Tokio.
 For Rust-Lightning clients which wish to make direct connections to Lightning P2P nodes, this is a simple alternative to implementing the required network stack, especially for those already using Tokio.
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/lightning-persister/Cargo.toml b/lightning-persister/Cargo.toml
index 593e19a..5869f15 100644
--- a/lightning-persister/Cargo.toml
+++ b/lightning-persister/Cargo.toml
@@ -8,6 +8,7 @@ description = """
 Utilities for LDK data persistence and retrieval.
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/lightning-rapid-gossip-sync/Cargo.toml b/lightning-rapid-gossip-sync/Cargo.toml
index 17d4687..1ae9eae 100644
--- a/lightning-rapid-gossip-sync/Cargo.toml
+++ b/lightning-rapid-gossip-sync/Cargo.toml
@@ -5,6 +5,7 @@ authors = ["Arik Sosman <git@arik.io>"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/lightningdevkit/rust-lightning"
 edition = "2021"
+rust-version = "1.75"
 description = """
 Utility to process gossip routing data from Rapid Gossip Sync Server.
 """
diff --git a/lightning-tests/Cargo.toml b/lightning-tests/Cargo.toml
index 1bae68b..9e0294b 100644
--- a/lightning-tests/Cargo.toml
+++ b/lightning-tests/Cargo.toml
@@ -6,6 +6,7 @@ license = "MIT OR Apache-2.0"
 repository = "https://github.com/lightningdevkit/rust-lightning/"
 description = "Tests for LDK crates"
 edition = "2021"
+rust-version = "1.75"
 
 [features]
 
diff --git a/lightning-transaction-sync/Cargo.toml b/lightning-transaction-sync/Cargo.toml
index 4810014..50e48af 100644
--- a/lightning-transaction-sync/Cargo.toml
+++ b/lightning-transaction-sync/Cargo.toml
@@ -8,6 +8,7 @@ description = """
 Utilities for syncing LDK via the transaction-based `Confirm` interface.
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/lightning-types/Cargo.toml b/lightning-types/Cargo.toml
index 15b40aa..2abaaa9 100644
--- a/lightning-types/Cargo.toml
+++ b/lightning-types/Cargo.toml
@@ -8,6 +8,7 @@ description = """
 Basic types which are used in the lightning network
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 rustdoc-args = ["--cfg", "docsrs"]
diff --git a/lightning/Cargo.toml b/lightning/Cargo.toml
index 94919ef..47ae12f 100644
--- a/lightning/Cargo.toml
+++ b/lightning/Cargo.toml
@@ -9,6 +9,7 @@ A Complete Bitcoin Lightning Library in Rust.
 Handles the core functionality of the Lightning Network, allowing clients to implement custom wallet, chain interactions, storage and network logic without enforcing a specific runtime.
 """
 edition = "2021"
+rust-version = "1.75"
 
 [package.metadata.docs.rs]
 features = ["std", "dnssec"]