Add GitHub issue notification when deploy job fails

There doesn't appear to be any GitHub issue notification setup for when the deploy job fails, as evidenced by #5055 not coming to our attention. It's a pretty important job so we do want to be notified.

@monperrus can you setup the notification?

Start by locating the deploy job and any existing notification configuration in the repository's GitHub Actions setup. Use the failure described in #5055 as the check case; done means a failed deploy produces the requested GitHub issue notification.

Written by the indexing model from the issue text.