fix(frontend/pageMetadata): ページタイトルが更新されない問題 (#13289)

Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
Co-authored-by: syuilo <4439005+syuilo@users.noreply.github.com>

packages/frontend/src/pages/welcome.vue

@@ -29,8 +29,8 @@ const headerActions = computed(() => []);
 
 const headerTabs = computed(() => []);
 
-definePageMetadata(computed(() => ({
+definePageMetadata(() => ({
 	title: instanceName,
 	icon: null,
-})));
+}));
 </script>