Fix IDE warnings (#12281)

### What problem does this PR solve?

As title

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

rag/utils/oss_conn.py

@@ -42,14 +42,16 @@ class RAGFlowOSS:
             # If there is a default bucket, use the default bucket
             actual_bucket = self.bucket if self.bucket else bucket
             return method(self, actual_bucket, *args, **kwargs)
+
         return wrapper
-    
+
     @staticmethod
     def use_prefix_path(method):
         def wrapper(self, bucket, fnm, *args, **kwargs):
             # If the prefix path is set, use the prefix path
             fnm = f"{self.prefix_path}/{fnm}" if self.prefix_path else fnm
             return method(self, bucket, fnm, *args, **kwargs)
+
         return wrapper
 
     def __open__(self):
@@ -171,4 +173,3 @@ class RAGFlowOSS:
                 self.__open__()
                 time.sleep(1)
         return None
-