Relates to https://github.com/coder/dogfood/pull/189
Closes https://github.com/coder/internal/issues/1021
- Adds new script `scripts/should_deploy.sh` which implements the
algorithm in the linked issue
- Changes the `ci.yaml` workflow to run on release branches
- Moves the deployment steps out of `ci.yaml` into a new workflow
`deploy.yaml` for concurrency limiting purposes
- Changes the behavior of image tag pushing slightly:
- Versioned tags will no longer have a `main-` prefix
- `main` branch will still push the `main` and `latest` tags
- `release/x.y` branches will now push `release-x.y` tags
- The deploy job will exit early if `should_deploy.sh` returns false
- The deploy job will now retag whatever image it's about to deploy as
`dogfood`
Dean Sheather