They mirror to GitHub regularly, but development still happens in CVS. They are building “got” as a potential replacement that allows git-driven development while following OpenBSD’s idiosyncratic approach: https://gameoftrees.org/goals.html
My guess is they based this on the similar NetBSD port but I don’t know where the repo is.
Edit: sibling commenter found it
The GitHub mirror of the equivalent NetBSD package is here [1].
[1] https://github.com/NetBSD/pkgsrc/tree/trunk/emulators/wine