build: add support for gcr-4
The gcr-3.90 development release finally ships with gtk3 and gtk4 support and has been imported into Fedora 37. Good.
The new libraries available are: gcr-4-gtk3 and gcr-4-gtk4 for the GUI part, replacing gcr-3 as well as new version of gck: gck-2 superseding gck-1.