Major Description
Considering the upcoming improvements on the result inconsistencies between traditional Pickled Python UDFs and Arrow-optimized Python UDFs, we'd better block the feature, otherwise, users who try out the feature will expect behavior changes in the next release.
In addition, since Spark Connect Python Client(SCPC) has been introduced in Spark 3.4, we'd better ensure the feature is ready in both vanilla PySpark and SCPC at the same time for compatibility.
