Please upgrade from GTK 2 to GTK 3

[olekw]

As noted in the Debian bug, GTK 2 was superseded by GTK 3 in 2011, nine years ago. GTK 2 no longer receives any significant upstream maintenance, and in particular does not get feature development for new features like UI scaling on high-pixel-density displays (HiDPI) and native Wayland support. GTK 3 is in maintenance mode and GTK 4 is approaching release, so it seems like a good time to be thinking about upgrading to GTK 3.

A porting guide is provided in the GTK 3 documentation.