APIView should somehow block PRs from being merged in GitHub

[heaths]

With swagger/Cadl support coming online for APIView, I feel one important feature that's needed is to somehow block PRs on GitHub from being merged while there are unresolved comments. Ideally, showing those comments on appropriate lines in the PR would be nice so we're not forced to use separate tools- GitHub and APIView - but perhaps consider that a stretch or I can open another issue.

At the very least, perhaps some sort of hook to prevent merging while there are unresolved comments. I assume links will still be added to PRs so that service teams know to look at APIView, but randomized assignees for merging need to know why a PR is blocked and not be able to override e.g., a required check.

[mikekistler]

Maybe APIView should add an "approved" label on the PR when approved in APIView.

[heaths]

That could work. We already have a convention of using green "Approved-{Topic}" labels for purposes like this. Easy to override, but at least there's a paper trail.

[mikekistler]

Currently this is a manual process -- one of the API Stewards assigned as a reviewer adds the "APIStewardshipBoard-signedOff" label and that is the signal that the PR is okay to merge (from the POV of the stewardship board).

Issue #6184 should put the checks in place to block a merge until the "signedOff" label has been applied.