fix(frontend): popupのemit型が正しく利用できるように修正 (#16826)

* fix(frontend): popupのemit型が正しく利用できるように修正

* fix: revert unnecessary code (for testing purpose)

* fix lint

* fix type errors

* fix types

* add comment

* fix

* fix

* fix: OverloadToUnionの仕組みを変更

* add comments, clean up

* fix lint

* fix types

* clean up [ci skip]

* fix

* add comments [ci skip]

packages/frontend/src/components/MkAnnouncementDialog.vue

@@ -4,7 +4,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 -->
 
 <template>
-<MkModal ref="modal" :zPriority="'middle'" :preferType="'dialog'" @closed="$emit('closed')" @click="onBgClick">
+<MkModal ref="modal" :zPriority="'middle'" :preferType="'dialog'" @closed="emit('closed')" @click="onBgClick">
 	<div ref="rootEl" :class="$style.root">
 		<div :class="$style.header">
 			<span :class="$style.icon">
@@ -44,6 +44,10 @@ const props = defineProps<{
 	announcement: Misskey.entities.Announcement;
 }>();
 
+const emit = defineEmits<{
+	(ev: 'closed'): void;
+}>();
+
 const rootEl = useTemplateRef('rootEl');
 const bottomEl = useTemplateRef('bottomEl');
 const modal = useTemplateRef('modal');