Notify when releases fail #2193

Releases can fail silently. The contributors responsible for those changes will not be informed of this unless they actively track the release workflow in Actions.

When this occurs,

• all PRs associated with that release should get a comment in the (closed) PR thread notifying about the failure
• perhaps gchat or other channel should also be updated

Likewise, when releases pass

• all associated PRs should be moved from "Done" column to "Release" column, if they are part of a project.
• those PRs should get a happy message

That way, PR subscribers will receive a notification

Questions

How, exactly, can we 'associate' a PR with a release PR? at worst, presumably we could store the relationship in a json file, perhaps in the wiki repo, or on a special branch