rm valid filename

csst_dfs_client/common/utils.py

 from datetime import datetime
-import re
-
-def is_valid_filename(file_name: str) -> bool:
-    pattern = r'^.*\..*$'
-    if re.match(pattern, file_name):
-        return True
-    else:
-        raise False
     
 def is_valid_datetime_format(date_str: str, format='%Y-%m-%d %H:%M:%S') -> bool:
     try: