It seems like to be a serious CI platform they really need to change Windows and Mac binaries for runners so you can build for those platforms.
And this is more of a Forgejo issue than a Codeberg issue specifically.
But also, I’d also throw out there the idea that CI doesn’t have to be at the same website as your source control. It’s nice that GitHub actions are conveniently part of the product but it’s not even really the top CI system out there.