meson: Bump to GTK 4.15.2 and libadwaita 1.6.beta

meson.build

@@ -71,8 +71,8 @@ add_project_arguments(compiler_flags, language: 'c')
 dvdread_dep = dependency('dvdread', version: '>= 4.2.0')
 gio_unix_dep = dependency('gio-unix-2.0', version: '>= 2.31.0')
 gmodule_dep = dependency('gmodule-2.0')
-gtk_dep = dependency('gtk4', version: '>= 4.13.4')
-libadwaita_dep = dependency('libadwaita-1', version: '>= 1.5')
+gtk_dep = dependency('gtk4', version: '>= 4.15.2')
+libadwaita_dep = dependency('libadwaita-1', version: '>= 1.6.beta')
 liblzma_dep = dependency('liblzma', version: '>= 5.0.5')
 libnotify_dep = dependency('libnotify', version: '>= 0.7')
 libsecret_dep = dependency('libsecret-1', version: '>= 0.7')