I think it can be done half/half. Do some, well-defined builds at GitHub and pull in for testing. Another comment tells that some users needed 10+ minutes to get a lock to pass their tests through CI, so maybe some sanity tests can be offloaded to GitHub actions.
I'm not claiming that my comment was 100% accurate, but they plan to move some of the CI to GitHub, at least.
> but they plan to move some of the CI to GitHub, at least
Really? I've seen no indication of that anywhere, and I'd be amazed if they did.
They're not using github PRs, and github actions really fights against other development workflows... not to mention they already have invested a lot in TaskCluster, and specialized it to their needs.
I'm not claiming that my comment was 100% accurate, but they plan to move some of the CI to GitHub, at least.