[mergebot] Fix mergebot allow revert of codev diff (#91975)
mergebot was allowing non facebook-github-bot users to revert codev diffs when it shouldnt be allowed
Fixes https://github.com/pytorch/test-infra/issues/1381
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91975
Approved by: https://github.com/ZainRizvi, https://github.com/kit1980, https://github.com/malfet
