clean code

packages/app/src/server/service/activity.ts

@@ -1,8 +1,5 @@
-import { Types } from 'mongoose';
 import Crowi from '../crowi';
 
-import { ActivityDocument } from '../models/activity';
-
 import ActivityDefine from '../util/activityDefine';
 import { getModelSafely } from '../util/mongoose-utils';