Coqbot should report the reason it suggests not minimizing targets when we request that it minimize them anyway, at least when there are no suggested targets.

[JasonGross]

The issue is that ci-analysis also fails on master. Coqbot should report the reason it suggests not minimizing targets when we request that it minimize them anyway, at least when there are no suggested targets.

Originally posted by @JasonGross in https://github.com/coq/coq/issues/15807#issuecomment-1078635664