Hello Guix!

These are my WIP patches to add the gtk4 crates. Several Gnome and Gtk applications depend on this crate (Authenticator, Fractal, Shortwave, etc).

I based the patches on c-u-f because the master branch isn't building on my machine for unrelated reasons I have yet to explore. Regardless, there should be no conflicts.

Several of the dependency package definitions are unedited from `guix import`, so please do let me know if you think I should change them.

Looking forward to your feedback!

Kind regards,
Nicholas von Klitzing