fix: エラーハンドリングでの保守性の確保

- catchブロックでのeという変数名は混同の危険性があるため利用しない
- 保守性のため型チェックでのエラーハンドリングを行う

packages/backend/src/core/entities/NotificationEntityService.ts

@@ -5,7 +5,7 @@
 
 import { Inject, Injectable } from '@nestjs/common';
 import { ModuleRef } from '@nestjs/core';
-import { In } from 'typeorm';
+import { EntityNotFoundError, In } from 'typeorm';
 import { DI } from '@/di-symbols.js';
 import type { FollowRequestsRepository, NotesRepository, MiUser, UsersRepository } from '@/models/_.js';
 import { awaitAll } from '@/misc/prelude/await-all.js';
@@ -139,9 +139,9 @@ export class NotificationEntityService implements OnModuleInit {
 		// #endregion
 
 		const needsRole = notification.type === 'roleAssigned';
-		const role = needsRole ? await this.roleEntityService.pack(notification.roleId).catch((e) => {
-			if (e.name === 'EntityNotFoundError') return null;
-			throw e;
+		const role = needsRole ? await this.roleEntityService.pack(notification.roleId).catch((err) => {
+			if (err instanceof EntityNotFoundError) return null;
+			throw err;
 		}) : undefined;
 		// if the role has been deleted, don't show this notification
 		if (needsRole && !role) {