refactor(backend): 存在確認のfindOneByをexistに置き換え (#11224)

* refactor(backend): 存在確認の`findOneBy`を`exist`に置き換え

* cleanup

packages/backend/src/server/api/endpoints/auth/accept.ts

@@ -58,12 +58,14 @@ export default class extends Endpoint<typeof meta, typeof paramDef> {
 			const accessToken = secureRndstr(32);
 
 			// Fetch exist access token
-			const exist = await this.accessTokensRepository.findOneBy({
-				appId: session.appId,
-				userId: me.id,
+			const exist = await this.accessTokensRepository.exist({
+				where: {
+					appId: session.appId,
+					userId: me.id,
+				},
 			});
 
-			if (exist == null) {
+			if (!exist) {
 				const app = await this.appsRepository.findOneByOrFail({ id: session.appId });
 
 				// Generate Hash