Github can use/offer Pijul. Sure they named themselves after technology, but nothing prevents them to offer other control systems.
Nevertheless, I'll assume you're not playing some weird game, and that git is trademarked, in which case I stand corrected. It's therefore safe to assume that GitHub and GitLab are allowed to use git in their trade names, according to the holder of the trademark. Unlike a notional "SVNHub", the trademark violation in those two names is quite clear, so they either have explicit permission and pay a license, or Linus (presumably) is ok with their existence.
I invite you to repeat my search. Unfortunately, the USPTO trademark database search interface is not bery intuitive, so be prepared for some trial and error if you do.