Run the pr-label check on PR closed action and validate closed_by (#71917)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/68459
This PR implements reminder to assign the release notes and topic labels to each PR when merged. Here is an example of the message that set on the issue related to PR:
> Hey atalman. You merged this PR, but no release notes category and topic labels were added. >
> The list of valid release and topic labels is available https://github.com/pytorch/pytorch/labels?q=release+notes+or+topic
Tested by manually running process_commit.py script in standalone mode passing following commit_hash = "e020414cb25cd763103f77a10c6225ce27cbbb6e" which should resolve to this PR
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71917
Reviewed By: malfet
Differential Revision: D33847058
Pulled By: atalman
fbshipit-source-id: 370e0928b792df721b216a8e08b22253f03abda3
(cherry picked from commit dfa86f440f155a3328ad4149a92ea48fcd72f158)
