feat: comment when auto merge/hardreset fails

[wei]

Currently GitHub returns an error when Pull tries to merge into a protected branch. The PR will just stay open ready to be manually merged.

An improvement will be commenting on the PR when this happens.

[wei]

One reason PRs fail to be merged automatically is due to changes in .github/workflows files (GitHub Apps do not have write access to it)

[jefferycline1]

😀