It's a sad situation that if you desire exposure and community building you must maintain a fork on Github, but that's how it is for smaller projects. I am in a similar situation, with some of my projects with main repos hosted on sourcehut, but most of external engagement comes from clones on github. It is what it is, and we do what we must. :)
It looks like they are a pragmatic project that prefers to have contributors to being ideologically pure. It's not like there isn't an official repository hosted on gitea: https://gitea.com/gitea
It's a sad situation that if you desire exposure and community building you must maintain a fork on Github, but that's how it is for smaller projects. I am in a similar situation, with some of my projects with main repos hosted on sourcehut, but most of external engagement comes from clones on github. It is what it is, and we do what we must. :)