Exclude channel notes from featured polls (#13838)

* feat(backend): add `channelId` to `MiPoll` as a Denormalized field

* feat(backend): option to exclude polls in channels

* chore: exclude channel notes from featured polls

* docs(changelog): みつけるのアンケート欄にてチャンネルのアンケートが含まれてしまう問題を修正

* fix: missing license header

packages/frontend/src/pages/explore.featured.vue

@@ -29,6 +29,9 @@ const paginationForPolls = {
 	endpoint: 'notes/polls/recommendation' as const,
 	limit: 10,
 	offsetMode: true,
+	params: {
+		excludeChannels: true,
+	},
 };
 
 const tab = ref('notes');