They've been meaning to migrate for a while now, but have had various blockers.

https://github.com/go-gitea/gitea/issues/1029

We are actively working on it, everything other than the main repo is on gitea.com and a lot of that is also being converted to dogfood actions.

The main repo, however, has a lot of issues/prs/etc metadata and so migrating is a bit harder.