From the comments, Forgejo is also already working on implementing ForgeFed, an ActivityPub extension specifically designed for software forges [0]. Judging from the issue, it looks like they're well on their way [1].
I dislike even federated social media, but this is a use for federation I approve of wholeheartedly. The friction of having to create accounts on X forges (where X is the number of projects that self-host) is a huge moat for GitHub, and federation could solve that very handily and create an environment where FOSS projects can feasibly host their own code away from Microsoft's control without horribly inconveniencing everyone who wants to participate.