Fix lifetime elision warnings introduced by rustc 1.89

The just-released rustc 1.89 added a new `mismatched-lifetime-syntaxes`
lint which had two warnings pop up. We fix these here.

Author: tnull

src/chain/bitcoind_rpc.rs

@@ -296,7 +296,7 @@ impl BlockSource for BitcoindRpcClient {
 		Box::pin(async move { self.rpc_client.get_block(header_hash).await })
 	}
 
-	fn get_best_block(&self) -> AsyncBlockSourceResult<(BlockHash, Option<u32>)> {
+	fn get_best_block(&self) -> AsyncBlockSourceResult<'_, (BlockHash, Option<u32>)> {
 		Box::pin(async move { self.rpc_client.get_best_block().await })
 	}
 }

src/tx_broadcaster.rs

@@ -36,7 +36,9 @@ where
 		Self { queue_sender, queue_receiver: Mutex::new(queue_receiver), logger }
 	}
 
-	pub(crate) async fn get_broadcast_queue(&self) -> MutexGuard<mpsc::Receiver<Vec<Transaction>>> {
+	pub(crate) async fn get_broadcast_queue(
+		&self,
+	) -> MutexGuard<'_, mpsc::Receiver<Vec<Transaction>>> {
 		self.queue_receiver.lock().await
 	}
 }