refactor: refactoring imports

将来ESMに移行しやすいように
Related: #7658

なんかmochaが起動しなくなってるけど理由不明
すぐ直したい

src/server/api/endpoints/channels/featured.ts

@@ -1,5 +1,5 @@
-import define from '../../define';
-import { Channels } from '../../../../models';
+import define from '../../define.js';
+import { Channels } from '@/models/index.js';
 
 export const meta = {
 	tags: ['channels'],