gtk+3: Update 3.24.43 -> 3.24.51

gtk+3: Update 3.24.43 -> 3.24.51

According to https://www.gtk.org/docs/installations/linux/#gtk-v3x the new
place for downloads is download.gnome.org aka $GNOME_MIRROR (ftp.g.o
redirects to this). And new versions are without `+`.

Update opengl.patch, handle new `is_gl_context_current`.

Overview of Changes in GTK+ 3.24.51, 29-09-2025
===============================================

* Wayland:
 - Force window titles to be valid utf8
 - Flush tablet events when neccessary

* X11:
 - Avoid a use-after-free with threads

* Windows:
 - Avoid min/max buttons for dialogs

* Images:
 - Replace a few calls to gdk_pixbuf_get_pixels
   with read_pixels to avoid thread-safety issues

* GL:
 - Try harder to keep the GL context current

* Input:
 - Make compose file parsing more robust

* Translation updates:
 Catalan
 Esperanto
 Persian

Overview of Changes in GTK+ 3.24.50, 07-08-2025
===============================================

* Themes:
 - Add a progress-working-symbolic icon
 - Support strokes in symbolic icons
 - Update theme CSS
 - Remove hardcoded Cantarell font

* GtkShortcutsWindow:
 - Differentiate all keypad symbols visually

* GtkApplication:
 - Register unsandboxed apps with the portals

* macOS:
 - Remove redundant NSView calls
 - Fix some memory leaks
 - Don't try to use the file transfer portal

* Windows:
 - Always mark windows as minimizable

* X11
 - Fix problems with gtk_window_get_geometry

* Wayland:
 - Fix a crash

* Input:
 - Make compose sequence visuals configurable

* Printing:
 - Fix the build with libcups 3
 - Support gnome-papers as previewer

* Translation updates
 Nepali
 Persian
 Uzbek (Latin)

Overview of Changes in GTK+ 3.24.49, 05-03-2025
===============================================

* Fix a crash in GtkIMContext

* Fix crashes in DND with GtkPlug/GtkSocket

* Wayland:
 - Fix erroneous crossing events, causing menus to malfunction
 - Support the cursor-shape protocol

* X11:
 - Enforce size limits on windows, preventing lockups

* macOS:
 - Fix pen tilt handling

* Translation updates
 Bulgarian
 Thai

Overview of Changes in GTK+ 3.24.48, 25-02-2025
===============================================

* Switch to the new ci-based release process

Overview of Changes in GTK+ 3.24.44, 24-01-2025
===============================================

* GtkFileChooser:
 - Stop replacing : (colon) with U+2236 (ratio)

* GtkEmojiChooser:
 - Update to Unicode 16 / CLDR 46

* GtkSpinButton:
 - Use semantically appropriate icon names
 - Make numeric spin buttons always LTR

* GtkEntry:
 - Stop guessing text direction from keyboard layout
 - Add a shortcut and context menu item to change text direction

* GtkEventControllerMotion:
 - Make enter and leave signals work

* Accessibility:
 - Use message dialog titles as names

* GDK:
 - Fix portal handling of gvfs files

* Wayland:
 - Support the xdg_foreign_v2 protocol
 - Try to fix monitor geometry on sway
 - Improve font setting fallback
 - Use a better default cursor size
 - Fix a crash during DND

* macOS:
 - Fix a UI hang

* Translation updates:
 Bulgarian
 Farsi
 Hindi
 Hungarian
 Icelandic
 Latvian
 Serbian

Signed-off-by: Jörg Sommer <joerg.sommer@navimatix.de>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>