The forge runner takes one job at a time, so every superseded push or PR sync piled up
behind the one before it and the dev preview run waited behind runs for merged heads.
Pull-request workflows get a group per workflow and PR number; the dev preview gets its
own group, so a newer dev push cancels an older one and PR runs never cancel it.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>