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/models/entities/meta.ts

@@ -1,7 +1,7 @@
 import { Entity, Column, PrimaryColumn, ManyToOne, JoinColumn } from 'typeorm';
-import { User } from './user';
-import { id } from '../id';
-import { Clip } from './clip';
+import { User } from './user.js';
+import { id } from '../id.js';
+import { Clip } from './clip.js';
 
 @Entity()
 export class Meta {