– https://github.com/go-gitea/gitea/blob/main/LICENSE
If you don't want your software used like that, don't choose this licence.
You can't post-hoc decide how people behave.
But even if there were some "ethical reason" to do this, I don't think Gitea is the right project to play up as a victim. Their homepage [2] doesn't mention that Gitea itself is a fork either. Their Readme does, but is this so much better?
[1]: https://forgejo.org/2022-12-15-hello-forgejo/ [2]: https://about.gitea.com/