revert: 回滚校验字典code代码修改

src/main/java/com/youlai/boot/system/service/impl/DictServiceImpl.java

@@ -67,7 +67,9 @@ public class DictServiceImpl extends ServiceImpl<DictMapper, Dict> implements Di
         // 校验 code 是否唯一
         String dictCode = entity.getDictCode();
 
-        long count = this.baseMapper.getDictCodeCount(dictCode);
+        long count = this.count(new LambdaQueryWrapper<Dict>()
+            .eq(Dict::getDictCode, dictCode)
+        );
 
         Assert.isTrue(count == 0, "字典编码已存在");