opt: func

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/pages/common/common_search_controller.dart

@@ -15,7 +15,7 @@ abstract class CommonSearchController<R, T> extends CommonListController<R, T> {
   }
 
   @override
-  Future onRefresh() {
+  Future<void> onRefresh() {
     if (editController.value.text.isEmpty) {
       return Future.value();
     }