To be fair this has more to do with Github Actions than Github, which from the beginning was never really going to rival any professional solution.
The people at Zig should use proper CI tools and not something that a big service provider is offering as an afterthought.
What is wrong with GitHub Actions other than the outages? I've never hit a issue myself.
Our CI workflow literally just invokes a plain old shell script (which is runnable outside CI). We really don't need an overcomplicated professional CI/CD solution.
One of the nice things about switching to Forgejo Actions is that the runner is lightweight, fast, and reliable - none of which I can say for the GitHub Actions runner. But even then, it's still more bloated than we'd ideally like; we don't need all the complexity of the YAML workflow syntax and Node.js-based actions. It'd also be cool for the CI system to integrate with https://codeberg.org/mlugg/robust-jobserver which the Zig compiler and build system will soon start speaking.
So if anything, we're likely to just roll our own runner in the future and making it talk to the Forgejo Actions endpoints.