Merge #363: Manual update to rustc (to nightly-2025-09-12)

81c85f8 Update Github CI to rustc nightly-2025-09-12 (Jamil Lambert, PhD)

Pull request description:

  The nightly version used in CI and when running `just fmt` is still on `nightly-2025-04-04`.

  - Fix the one lint error in the new nightly.
  - Update to `nightly-2025-09-12`

ACKs for top commit:
  tcharding:
    ACK 81c85f8

Tree-SHA512: 646887670bdd262cb9cfd8d6b485d9ddaa6d61a051fd5fe4b82859497ef18052faf7c598f67373bea310b334915d4009fa6df01b159ea57457111e90cbc75d5b

Author: tcharding

integration_test/tests/raw_transactions.rs

@@ -406,8 +406,10 @@ fn raw_transactions__test_mempool_accept__modelled() {
     let signed_tx = signed_model.tx;
 
     // Call testmempoolaccept with the valid (not yet broadcast) transaction.
-    let json: TestMempoolAccept =
-        node.client.test_mempool_accept(&[signed_tx.clone()]).expect("testmempoolaccept");
+    let json: TestMempoolAccept = node
+        .client
+        .test_mempool_accept(std::slice::from_ref(&signed_tx))
+        .expect("testmempoolaccept");
     #[cfg(feature = "v20_and_below")]
     type TestMempoolAcceptError = hex::HexToArrayError;
     let model: Result<mtype::TestMempoolAccept, TestMempoolAcceptError> = json.into_model();

nightly-version

@@ -1 +1 @@
-nightly-2025-04-04
+nightly-2025-09-12