Revert "feat: 個人宛てお知らせ機能 (#107)"

This reverts commit 7b1efd6b97.

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

@@ -4,7 +4,7 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import { In, IsNull, Not } from 'typeorm';
+import { In, Not } from 'typeorm';
 import * as Redis from 'ioredis';
 import _Ajv from 'ajv';
 import { ModuleRef } from '@nestjs/core';
@@ -250,11 +250,9 @@ export class UserEntityService implements OnModuleInit {
 			userId: userId,
 		});
 
-		const id = reads.length > 0 ? Not(In(reads.map(read => read.announcementId))) : undefined;
-		const count = await this.announcementsRepository.countBy([
-			{ id, userId: IsNull() },
-			{ id, userId: userId },
-		]);
+		const count = await this.announcementsRepository.countBy(reads.length > 0 ? {
+			id: Not(In(reads.map(read => read.announcementId))),
+		} : {});
 
 		return count > 0;
 	}