Allow users to opt-out of SIGTERM rescheduling on Kubernetes worker

[masonmenges]

Describe the current behavior

When a job runs through Kubernetes with a backoff limit of 0 we automatically reschedule the flow run based on the value of this env variable PREFECT_FLOW_RUN_EXECUTE_SIGTERM_BEHAVIOR

This is set automatically if the backoff_limit is 0 here even if the value is set as part of the job configuration through the work pool or job variables on a deployment.

prefect/src/integrations/prefect-kubernetes/prefect_kubernetes/worker.py

Lines 430 to 441 in 1ff07e6

	if isinstance(self.env, dict):
	self.env["PREFECT_FLOW_RUN_EXECUTE_SIGTERM_BEHAVIOR"] = "reschedule"
	elif not any(
	v.get("name") == "PREFECT_FLOW_RUN_EXECUTE_SIGTERM_BEHAVIOR"
	for v in self.env
	):
	self.env.append(
	{
	"name": "PREFECT_FLOW_RUN_EXECUTE_SIGTERM_BEHAVIOR",
	"value": "reschedule",
	}
	)

Describe the proposed behavior

Ideally a user would be able to set PREFECT_FLOW_RUN_EXECUTE_SIGTERM_BEHAVIOR to some value other than reschedule to opt out of this behavior.

Example Use

No response

Additional context

No response

[svatopluk-sperka]

Yes, this is what we would need. Current baked in strategy is a bit aggressive in certain cases.