update comment and runtime message for get_berror_dict_identity (NOAA…

…-EMC#1313)

ush/python/pygfs/task/atm_analysis.py

@@ -301,12 +301,15 @@ def get_berror_dict(self, config: Dict[str, Any]) -> Dict[str, List[str]]:
     @staticmethod
     @logit(logger)
     def _get_berror_dict_identity(config: Dict[str, Any]) -> Dict[str, List[str]]:
-        """Compile a dictionary of atm identity background error files to copy
-        This method is not implemented yet.
+        """Placeholder for atm identity background error files to copy
+
+        This method currently does nothing since the identity background error
+        does not require any external files.
 
         This is a private method and should not be accessed directly.
+
         """
-        raise NotImplementedError("Identity background error not yet implemented")
+        logger.info(f"Identity background error does not use staged files.  Return empty dictionary")
 
     @staticmethod
     @logit(logger)