crates: upgrade to 2024 rust edition

I've ran `cargo fix --edition` and three changes were noticeable:
- set_var is now unsafe, i've added a SAFETY comment on each to explain why
  this is fine here.
- conversions of several if let to match because of the new if let temporary scope
  I have reviewed and restored all of them since the behaviour was the same on each.
- the macro expr was converted to expr_2021 in the lsps plugin, i have reverted those
  aswell since we don't use const or _ expressions

Changelog-None

Author: daywalker90

cln-grpc/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "cln-grpc"
 version = "0.6.0"
-edition = "2021"
+edition = "2024"
 license = "MIT"
 description = "The Core Lightning API as grpc primitives. Provides the bindings used to expose the API over the network."
 homepage = "https://github.com/ElementsProject/lightning/tree/master/cln-grpc"

cln-rpc/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "cln-rpc"
 version = "0.6.0"
-edition = "2021"
+edition = "2024"
 license = "MIT"
 description = "An async RPC client for Core Lightning."
 homepage = "https://github.com/ElementsProject/lightning/tree/master/cln-rpc"

plugins/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "cln-plugin"
 version = "0.6.0"
-edition = "2021"
+edition = "2024"
 license = "MIT"
 description = "A CLN plugin library. Write your plugin in Rust."
 homepage = "https://github.com/ElementsProject/lightning/tree/master/plugins"

plugins/bip353-plugin/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "cln-bip353"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 license = "MIT"
 description = "BIP-353 lookups"
 homepage = "https://github.com/ElementsProject/lightning/tree/master/plugins"

plugins/bip353-plugin/src/main.rs

@@ -15,11 +15,22 @@ mod config;
 
 #[tokio::main(flavor = "current_thread")]
 async fn main() -> Result<(), anyhow::Error> {
+    unsafe {
+        // SAFETY:
+        // `std::env::set_var` is unsafe in Rust 2024 because environment variables
+        // are process-global and unsynchronized. Concurrent reads/writes from
+        // multiple threads can cause undefined behavior.
+        //
+        // This call happens at process startup, before any threads are spawned and
+        // before any code that may read environment variables is executed.
+        // Therefore, no concurrent access is possible.
+        std::env::set_var(
+            "CLN_PLUGIN_LOG",
+            "cln_plugin=info,cln_rpc=info,cln_bip353=trace,warn",
+        )
+    };
+
     log_panics::init();
-    std::env::set_var(
-        "CLN_PLUGIN_LOG",
-        "cln_plugin=info,cln_rpc=info,cln_bip353=trace,warn",
-    );
 
     let plugin = match Builder::new(tokio::io::stdin(), tokio::io::stdout())
         .rpcmethod_from_builder(

plugins/currencyrate-plugin/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "cln-currencyrate"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 license = "MIT"
 description = "Fetches currency rates"
 homepage = "https://github.com/ElementsProject/lightning/tree/master/plugins"

plugins/currencyrate-plugin/src/main.rs

@@ -30,11 +30,22 @@ struct PluginState {
 
 #[tokio::main(flavor = "current_thread")]
 async fn main() -> Result<(), anyhow::Error> {
+    unsafe {
+        // SAFETY:
+        // `std::env::set_var` is unsafe in Rust 2024 because environment variables
+        // are process-global and unsynchronized. Concurrent reads/writes from
+        // multiple threads can cause undefined behavior.
+        //
+        // This call happens at process startup, before any threads are spawned and
+        // before any code that may read environment variables is executed.
+        // Therefore, no concurrent access is possible.
+        std::env::set_var(
+            "CLN_PLUGIN_LOG",
+            "cln_plugin=info,cln_rpc=info,cln_currencyrate=debug,warn",
+        )
+    };
+
     log_panics::init();
-    std::env::set_var(
-        "CLN_PLUGIN_LOG",
-        "cln_plugin=info,cln_rpc=info,cln_currencyrate=debug,warn",
-    );
 
     let _ = rustls::crypto::ring::default_provider().install_default();
 

plugins/grpc-plugin/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-edition = "2021"
+edition = "2024"
 name = "cln-grpc-plugin"
 version = "0.6.0"
 

plugins/grpc-plugin/src/main.rs

@@ -37,10 +37,20 @@ const OPTION_GRPC_MSG_BUFFER_SIZE : options::DefaultIntegerConfigOption = option
 
 #[tokio::main(flavor = "current_thread")]
 async fn main() -> Result<()> {
-    std::env::set_var(
-        "CLN_PLUGIN_LOG",
-        "cln_plugin=info,cln_rpc=info,cln_grpc=debug,debug",
-    );
+    unsafe {
+        // SAFETY:
+        // `std::env::set_var` is unsafe in Rust 2024 because environment variables
+        // are process-global and unsynchronized. Concurrent reads/writes from
+        // multiple threads can cause undefined behavior.
+        //
+        // This call happens at process startup, before any threads are spawned and
+        // before any code that may read environment variables is executed.
+        // Therefore, no concurrent access is possible.
+        std::env::set_var(
+            "CLN_PLUGIN_LOG",
+            "cln_plugin=info,cln_rpc=info,cln_grpc=debug,debug",
+        )
+    };
 
     let directory = std::env::current_dir()?;
 

plugins/grpc-plugin/src/tls.rs

@@ -101,8 +101,12 @@ fn generate_or_load_identity(
             params.key_usages.push(rcgen::KeyUsagePurpose::KeyCertSign);
         } else {
             params.is_ca = rcgen::IsCa::NoCa;
-            params.key_usages.push(rcgen::KeyUsagePurpose::DigitalSignature);
-            params.key_usages.push(rcgen::KeyUsagePurpose::KeyEncipherment);
+            params
+                .key_usages
+                .push(rcgen::KeyUsagePurpose::DigitalSignature);
+            params
+                .key_usages
+                .push(rcgen::KeyUsagePurpose::KeyEncipherment);
             params.key_usages.push(rcgen::KeyUsagePurpose::KeyAgreement);
         }
         params