[AIRFLOW-5315] TaskInstance now only overwrites executor_config when explicitly told…

[dimberman]

… to do so

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Fixes a bug where a user is unable to update executor_configs for TaskInstances

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[kaxil]

LGTM.

[kaxil]

I won't mind if we remove executor_config altogether from the TaskInstance table, so that it always uses the latest value.

Currently, it is only used in k8s executor AFAIK. Might need a note in UPDATING.md

[dimberman]

@kaxil where would you want to move it?

[kaxil]

I mean I am not able to find a use-case where we want the executor_config value to be refreshed from DB, so I do not mind if we simply remove it from DB and by default always take the latest value.

However, I am fine with the current change as well :)