Chore: Change from string to symbol as key of metadata

Author: Ho-s

src/common/decorators/typeorm.decorator.ts

@@ -1,6 +1,6 @@
 import { SetMetadata } from '@nestjs/common';
 
-export const TYPEORM_CUSTOM_REPOSITORY = 'TYPEORM_CUSTOM_REPOSITORY';
+export const TYPEORM_CUSTOM_REPOSITORY = Symbol('TYPEORM_CUSTOM_REPOSITORY');
 
 export function CustomRepository<T>(
   entity: new (...args: unknown[]) => T,