GTK4 and libadwaita update

[ZachBacon]

This updates gtk4 to 4.20.2 and libadwaita to 1.8.1

[lazka]

See #25319

[ZachBacon]

Alright, new gtk4 and libadwaita updates are in.

[ZachBacon]

@lazka what's your thoughts on the new gtk4 update?

[lazka]

Have there been any Windows fixes?

[ZachBacon]

the changelog has some win32 mentions

Overview of Changes in 4.20.3, 20-11-2025

• Bugs fixed:

  • Change in scrolling behavior
  • Unaligned access in gdk/gdkmemoryformat.c causes testsuite crashes on
    SPARC
  • Shaper: Cannot parse SVG
  • svg not scaled with display scale since switch to librsvg
  • GTK 4.18: Default GdkDisplay gets unreferenced when offscreen
    rendering via secondary display, causing crash
  • Feature: Add Win32 impl for gtk_file_launcher_open_containing_folder()
  • Vulkan: Validation: vkQueuePresentKHR(): PRESENT_AFTER_WRITE hazard
    detected.
  • ModelButton: Increasingly long hang when switching AdwMultiLayoutView

• Changes:

  • ci: Update Rust to 1.89.0
  • [4.20] vulkan: Disable YCbCr to RGB conversions for fallback formats
  • Backport non-smooth scrolling fixes to 4.20
  • [4.20] vulkan: Fix YUYV values when uploading images
  • [4.20] Fix touch dropdown selection properly
  • [4.20] emoji: Update data to CLDR 48

[lazka]

#25319 #26580