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/admin/relays/add.ts

@@ -1,8 +1,8 @@
 import { URL } from 'url';
 import $ from 'cafy';
-import define from '../../../define';
-import { addRelay } from '../../../../../services/relay';
-import { ApiError } from '../../../error';
+import define from '../../../define.js';
+import { addRelay } from '@/services/relay.js';
+import { ApiError } from '../../../error.js';
 
 export const meta = {
 	tags: ['admin'],