The nightly retry listed labeled closed PRs, then required each one to be
unlabeled, so no teardown ever ran. Nothing removed the label either, so every
failure re-queued every night. It also tested state == CLOSED, which misses
MERGED PRs. Teardown now clears the label only after a successful destroy, so
the scheduled list holds exactly the outstanding failures. Eligibility is "not
OPEN". Every job also requires the main branch, like deploy-relay.

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>