Each feature branch deploys a preview environment. A new commit should cancel an older preview deployment for the same branch without cancelling deployments for other branches. Which concurrency configuration is most appropriate?

1. Use one constant concurrency group named preview for every branch.
2. Group by workflow and github.ref; enable cancel-in-progress.
3. Set continue-on-error: true on every deployment step.
4. Use only strategy.max-parallel: 1.