0cab43ed89
The auto-merge step runs in a job with no actions/checkout, so gh could not
infer the repository from a git remote and failed with 'not a git repository'
(#719 follow-up). Set GH_REPO=${{ github.repository }} so gh pr list/review/
merge work without a checkout — same fix as the whatsnew workflow (2a5f0a8).
Confirmed working otherwise: with RELEASE_PLEASE_TOKEN set, release PR #721 is
now PAT-authored and its required checks run automatically (no manual approval).