some async refactorings

app/lib/features/search_browser/presentation/screens/browser.dart

@@ -305,7 +305,7 @@ class KagiScreen extends HookConsumerWidget {
                     lastBackButtonPress.value = null;
 
                     if (activeWebView?.key != null && webViews.length > 1) {
-                      await ref
+                      ref
                           .read(webViewRepositoryProvider.notifier)
                           .closeTab(activeWebView!.key!);
                       return true;

app/lib/features/search_browser/presentation/widgets/sheets/view_tabs_sheet.dart

@@ -29,10 +29,8 @@ class ViewTabsSheet extends HookConsumerWidget {
               label: const Text('New Tab'),
             ),
             TextButton.icon(
-              onPressed: () async {
-                await ref
-                    .read(webViewRepositoryProvider.notifier)
-                    .closeAllTabs();
+              onPressed: () {
+                ref.read(webViewRepositoryProvider.notifier).closeAllTabs();
               },
               icon: const Icon(Icons.delete),
               label: const Text('Close All'),