Description:
Allow filtering of PRs by review status

Justification:
If a PR is waiting for us to review it, we'll get to it eventually so we don't want it marked stale or auto-closed. However, we DO want the process applied to PRs where the PR submitter hasn't responded to requests for changes in a certain amount of time (review:changes_requested). Sure, we could manually add labels to the PRs to make them eligible or exempt from expiration but that defeats the purpose of the action. We could also write our own "pre-action" that automatically adds or removes labels based on review state but if we're going to do that, we might as well just do the expiration stuff ourselves as well.

I'm wondering... maybe a filter by generic search string would be better since you could call the REST /search/issues endpoint with it. Actually this is what the submitted PR does

Are you willing to submit a PR?
Yes! Sumitted.