We do our pre-releases on CI runners for convenience. GitHub automatically kicks-off a build when we git push.

When it comes time to do a real release, we can just run the job locally on our build machines (this is easier thanks to docker). Because our builds are reproducible, we can just check that the hash matches on our local build and the one from the free GitHub CI runners. That way we don’t have to trust the infrastructure, but we can use it for free & easy iteration before our final release.