There are are several open-source software projects that have been doing the same thing but on a self-hosted solution. GitLab instance like (GNOME, GTK, etc) or cgit (wireguard, Linux, etc) and so on. ReactOS has a backup mirror of this in case GitHub goes down. [2]
We really need to get away from the idea of 'centralising everything'.
[0] https://news.ycombinator.com/item?id=26469749