Switch Tech Preview to use GTK 4 branch
This will allow some extra testing for the GTK 4 branch before we pull the trigger to merge it into master. It's a lot easier to revert this commit than it is to revert such a merge.
This will allow some extra testing for the GTK 4 branch before we pull the trigger to merge it into master. It's a lot easier to revert this commit than it is to revert such a merge.