Remove unused imports (#12730)

packages/frontend/src/components/MkNotification.vue

@@ -136,7 +136,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 </template>
 
 <script lang="ts" setup>
-import { ref, shallowRef } from 'vue';
+import { ref } from 'vue';
 import * as Misskey from 'misskey-js';
 import MkReactionIcon from '@/components/MkReactionIcon.vue';
 import MkFollowButton from '@/components/MkFollowButton.vue';