chore: refuse to close PRs that are awaiting maintainer review (#28481)

Because of PRs that require cli integ tests run, some PRs have the automated review failing while awaiting review (and integ tests run). We shouldn't auto-close these as stale ever, since the ball is in our court. 

See #27882, where we were bad.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

.github/workflows/close-stale-prs.yml

@@ -25,5 +25,5 @@ jobs:
           important-checks-regex: AutoBuildv2Project1C6BFA3F
           warn-message: This PR has been in the STATE state for 3 weeks, and looks abandoned. To keep this PR from being closed, please continue work on it. If not, it will automatically be closed in a week.
           close-message: This PR has been deemed to be abandoned, and will be automatically closed. Please create a new PR for these changes if you think this decision has been made in error.
-          skip-labels: contribution/core,pr-linter/do-not-close
+          skip-labels: contribution/core,pr-linter/do-not-close,pr/needs-maintainer-review
           close-label: closed-for-staleness