[AIRFLOW-5581] Cleanly shutdown KubernetesJobWatcher for safe Scheduler shutdown on SIGTERM (#6237)
[AIRFLOW-5581] Cleanly shutdown KubernetesJobWatcher for safe Scheduler shutdown on SIGTERM (#6237)

(cherry picked from commit 12f916a432e7937f6f72d1b556196e863920f334)

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