Fix async/await for handle_expired_htlcs method

The handle_expired_htlcs method was calling an async function without awaiting it, causing a compiler warning. Made the method async and added proper await calls.

Author: Fernando Ledesma

src/lib.rs

@@ -635,7 +635,7 @@ impl Node {
 							return;
 						}
 						_ = tokio::time::sleep(Duration::from_secs(HTLC_EXPIRY_CHECK_INTERVAL_SECS)) => {
-								liquidity_handler.handle_expired_htlcs();
+								liquidity_handler.handle_expired_htlcs().await;
 						}
 						_ = liquidity_handler.handle_next_event() => {}
 					}

src/liquidity.rs

@@ -480,10 +480,10 @@ where
 		self.lsps4_client.as_ref().map(|s| (s.lsp_node_id, s.lsp_address.clone()))
 	}
 
-	pub(crate) fn handle_expired_htlcs(&self) {
+	pub(crate) async fn handle_expired_htlcs(&self) {
 		if let Some(lsps4_service_handler) = self.liquidity_manager.lsps4_service_handler() {
 			let now = SystemTime::now().duration_since(UNIX_EPOCH).unwrap_or_default().as_secs();
-			lsps4_service_handler.handle_expired_htlcs(now);
+			lsps4_service_handler.handle_expired_htlcs(now).await;
 		}
 	}