Fix repeated deletion attempts from adopted completed pods in kubernetes executor

[styndall]

This PR fixes an issue where adopted completed pods are processed over and over without ever being removed from the completed pod set. We saw thousands of duplicate pod deletion attempts after adoption events.

The fix simply removes the completed pods' state change from the main result_queue processing loop, processing them after the result_queue has been drained, and then removes them as they get processed, requeueing any failures.

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[jscheffl]

Looks good for me - but unfortunately I lag a bit of understanding of K8sExecutor. Therefore another reviewer would be good not that I miss some side-effect. But change looks reasonable

[styndall]

Looks good for me - but unfortunately I lag a bit of understanding of K8sExecutor. Therefore another reviewer would be good not that I miss some side-effect. But change looks reasonable

Is there someone specific I can ping to have a K8sExecutor expert's eyes on this?

[styndall]

@potiuk Are you able to review, or can you suggest the appropriate person?

[styndall]

Nevermind, fixed by this PR while I was waiting for review.