fix diff

Author: bhhalim

sagemaker-mlops/src/sagemaker/mlops/feature_store/feature_utils.py

@@ -731,4 +731,4 @@ def _cast_object_to_string(data_frame: pandas.DataFrame) -> pandas.DataFrame:
     """
     for label in data_frame.select_dtypes(["object", "O"]).columns.tolist():
         data_frame[label] = data_frame[label].astype("str").astype("string")
-    return data_frame
+    return data_frame