removing introduced new line

Author: davidsbatista

integrations/valkey/src/haystack_integrations/document_stores/valkey/document_store.py

@@ -1411,7 +1411,6 @@ def _metadata_field_to_doc_meta_key(field_name: str) -> str:
         key = ValkeyDocumentStore._normalize_metadata_field_name(field_name)
         return key[5:] if key.startswith("meta_") else key
 
-
     def _validate_metadata_field_names(self, metadata_fields: list[str]) -> None:
         """Ensure each field is configured for filtering; raise ValueError if not."""
         for name in metadata_fields: