some async refactorings

app/lib/features/web_view/domain/repositories/web_view.dart

@@ -35,11 +35,11 @@ class WebViewRepository extends _$WebViewRepository {
     state = {...state, webView.page.value.key: webView};
   }
 
-  Future<void> closeTab(Key key) async {
+  void closeTab(Key key) {
     state = Map.of(state)..remove(key);
   }
 
-  Future<void> closeAllTabs() async {
+  void closeAllTabs() {
     state = {};
   }
 }

app/lib/features/web_view/presentation/widgets/web_view_tab.dart

@@ -60,8 +60,8 @@ class WebViewTab extends HookConsumerWidget {
                   IconButton(
                     visualDensity:
                         const VisualDensity(horizontal: -4.0, vertical: -4.0),
-                    onPressed: () async {
-                      await ref
+                    onPressed: () {
+                      ref
                           .read(webViewRepositoryProvider.notifier)
                           .closeTab(page.key);
                     },