use ajv/dist/core

packages/backend/src/server/api/define.ts

@@ -6,7 +6,7 @@ import { ApiError } from './error';
 import { Schema, SchemaType } from '@/misc/schema';
 import { AccessToken } from '@/models/entities/access-token';
 import { ValidateFunction } from 'ajv';
-import { JTDDataType } from 'ajv/dist/types/jtd-schema';
+import { JTDDataType } from 'ajv/dist/core';
 import { apiLogger } from './logger';
 
 type SimpleUserInfo = {