The PostCommit Python ValidatesRunner Spark job is flaky

[github-actions]

The PostCommit Python ValidatesRunner Spark is failing over 50% of the time
Please visit https://github.com/apache/beam/actions/workflows/beam_PostCommit_Python_ValidatesRunner_Spark.yml?query=is%3Afailure+branch%3Amaster to see the logs.

[Abacn]

This is due to #30587 (comment) CC: @robertwb

[github-actions]

Reopening since the workflow is still flaky

[Amar3tto]

Culprit: #34641.
@shunping ptal