Codex PR review just hang forever

GitHub-hosted ubuntu-latest. openai/codex-action@v1.
Codex emits a complete JSON result, but the action never exits and later workflow
steps never begin. Reproduces on two PRs from different branches in the same repo;
the same workflow succeeds in another repo. Previous failures also hung in post-job
cleanup. Run Codex review remains active for 25+ minutes after final JSON output.