物理削除系の処理を削除

これらの処理はパフォーマンス的に現実的でないし、すべてのモデルの関係を把握している必要があり保守が困難
論理削除でなんとかする

src/models/following.ts

@@ -1,6 +1,5 @@
 import * as mongo from 'mongodb';
 import db from '../db/mongodb';
-import isObjectId from '../misc/is-objectid';
 
 const Following = db.get<IFollowing>('following');
 Following.createIndex(['followerId', 'followeeId'], { unique: true });
@@ -25,30 +24,3 @@ export type IFollowing = {
 		sharedInbox?: string;
 	}
 };
-
-/**
- * Followingを物理削除します
- */
-export async function deleteFollowing(following: string | mongo.ObjectID | IFollowing) {
-	let f: IFollowing;
-
-	// Populate
-	if (isObjectId(following)) {
-		f = await Following.findOne({
-			_id: following
-		});
-	} else if (typeof following === 'string') {
-		f = await Following.findOne({
-			_id: new mongo.ObjectID(following)
-		});
-	} else {
-		f = following as IFollowing;
-	}
-
-	if (f == null) return;
-
-	// このFollowingを削除
-	await Following.remove({
-		_id: f._id
-	});
-}