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/my-lists/list.vue

@@ -186,10 +186,10 @@ const headerActions = computed(() => []);
 
 const headerTabs = computed(() => []);
 
-definePageMetadata(computed(() => list.value ? {
-	title: list.value.name,
+definePageMetadata(() => ({
+	title: list.value ? list.value.name : i18n.ts.lists,
 	icon: 'ti ti-list',
-} : null));
+}));
 </script>
 
 <style lang="scss" module>