fix(ci): Check maintainer status against PR repo, not issue repo

When a PR references a cross-repo issue, the discussion participants
should be checked for maintainer status on the PR's target repo, not
the issue's repo. A sentry-python maintainer commenting on a
getsentry/sentry issue should still count as vetting the work.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: stephanie-anderson

.github/workflows/close-unvetted-pr.yml

@@ -196,7 +196,7 @@ jobs:
 
                 for (const user of usersToCheck) {
                   if (user === prAuthor) continue;
-                  if (await isMaintainer(ref.owner, ref.repo, user)) {
+                  if (await isMaintainer(repo.owner, repo.repo, user)) {
                     maintainerParticipated = true;
                     core.info(`Maintainer ${user} participated in ${ref.owner}/${ref.repo}#${ref.number}.`);
                     break;