Close the PR when the Promotion is aborted

[shabbir-saifee-cmm]

Checklist

• [ X ] I've searched the issue queue to verify this is not a duplicate feature request.
• [ X ] I've pasted the output of kargo version, if applicable.
• [ X ] I've pasted logs, if applicable.

Proposed Feature

Close the PR when the Promotion is aborted

Motivation

Suggested Implementation

[krancour]

Noting here that this ought not be addressed in a vacuum.

#2972 aims to make behavior configurable when a Promotion fails (or is aborted, I suppose).

It would be best to solve that first.

fwiw, it may better to work in the other direction. Instead of aborting the Promo and counting on that to close the PR, you could close the PR and count on that to fail the Promo. That already works.

[jessesuen]

Alternative proposal: #3639

[krancour]

#3639 + a close-pr step would work nicely.