What machines are used for Xcode Cloud builds? I couldn't find any information on that in the documentation. Is Xcode Cloud using M1/M2? Or is it going to use Apple CPU in the future?

Xcode Cloud is experiencing many problems with repository connection lately. Previously I had some issues with GitHub which disappeared after some time. And yesterday suddenly it stopped working with my Bitbucket repository. Now even if I try to add the repository again I always get 504 error: Why it is so unstable :(?