[AIRFLOW-4805] Add py_file as templated field in DataflowPythonOperator (#5451)
[AIRFLOW-4805] Add py_file as templated field in DataflowPythonOperator (#5451)


(cherry picked from commit d9ad100899a63eaf16ecc26c22b94c09c9c3e222)

owlabs/incubator-airflow,owlabs/incubator-airflow,owlabs/incubator-airflow,owlabs/incubator-airflow