libadwaita: upgrade 1.7.4 -> 1.7.5

libadwaita: upgrade 1.7.4 -> 1.7.5

Changelog:
- AdwAboutDialog/AdwAboutWindow
  - Fix a leak
- AdwAvatar
  - Fix custom image size with GTK 4.19.2
- AdwStyleManager
  - Fix loading font names when debug variables are set
- AdwTabOverview
  - Update window radius
- AdwToastOverlay
  - Fix a critical when showing a toast while hiding it
- Tests
  - Fix a leak

Signed-off-by: Simone Weiß <simone.p.weiss@posteo.com>
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>