This is interesting - as I understand it gitea supports work flows from the github marketplace - and I had just made a note to try and figure out how the ruby/setup-ruby[1] action actually works/is implemented - and from the looks/claims here - I guess it should just work with gitea?
I'm a huge fan of Gitea but saying that GH Actions are supported is a bit of a stretch. Everybody asked for CI/CD so they started working on it and yes you can test it but nobody sane would use it in a production setting.
Try running act against their own act fork and watch it vomit. I first had contact with act trying to get VSCodium to build locally, since their build system is/was entirely GitHub Actions based. The "well, that didn't work" was horrific to troubleshoot
git clone https://gitea.com/gitea/act.git
cd act
make build
./dist/local/act -j lint -W .github/workflows/checks.yml --verbose workflow_dispatch
echo good luck
As far as "Github actions are supported", I seem to recall they're using "act" for that and this issue appears to match my recollection, as well as my experience with act being fine for hello-world but 100% absolutely not a replacement for a formal CI/CD system: https://github.com/go-gitea/gitea/issues/13539#issuecomment-...
I will concede I have not tried keeping up with their fork <https://gitea.com/gitea/act> so maybe they cured all its ills