Log Message:
gtk4: updated to 4.12.1

Overview of Changes in 4.12.1, 25-08-2023
=========================================

* GtkGridView:
 - Fix a crash when scrolling

* GtkColumnView:
 - Fix a refcounting issue in the new scroll_to api

* GtkTreeView
 - Fix style classes for sort arrows

* GtkEntry:
 - Improve tracking of user changes (for undo)

* GtkNotebook:
 - Fix a critical when switching pages

* GtkColor/FontDialogButton:
 - Make these widgets activatable

* GtkMenuButton:
 - Fix problems with focus handling
 - Fix problems with DND

* Printing
 - Fix the cpdb backend build

* MacOS:
 - Make file filters work again

* GSK:
 - Fix issues with color matrix nodes

* Wayland:
 - Fix a crash with compositors other than gnome-shell

* Translation updates:
 Polish
 Swedish