Disable making changes directly on master

I accidentally made a change directly on master via the GH UI. We really should remove that option.


There was recently an issue with a discussion about this: Maintainers: please don't push directly to master/release branches · Issue #118661 · NixOS/nixpkgs · GitHub

As of a week ago, we have a transparent log of all direct pushes in the above issue.

I’m working on backporting automation so that we can have the same for release branches.

Once we see exactly what kind of commits are the exception, we can enforce restrictions by going through a simple RFC.

It just needs to be done and there’s a lot of bikeshedding, but we’ll get there!