Remove ability for author to unpublish own content?

When looking at the revision history, is there a way to disable for a specific role the ability to unpublish the revision? We want to prevent authors from unpublishing their own content, and instead use workflow to manage page deletions and removals.

I can't find anything in the existing permissions that does this, and it doesn't even seem to be something people are commonly seeking, so I am not certain if it is even possible.