Code review comment for ~shawn111/pmr:one-shot

The requirement I've seen for --one-shot comes from Jenkaas, and my understanding is that in that context the requirement would be more precisely described as an option that causes pmr to land at most one merge request. This doesn't meet that requirement.

Could you push the check down into the loop in merge_mergable_on_project instead? I'd suggest that the option description should then become something like "Only check for approved merge requests once, and land at most one of them."