Update xdg-desktop-portal-gtk to version 1.14.0 / rev 18 via SR 965320
    
    https://build.opensuse.org/request/show/965320
    by user iznogood + dimstar_suse
    - Update to version 1.14.0:
      + Add an implementation of the dynamic launcher portal
      + notification: Fix activation of default action with target
      + Updated translations.
    - Update to version 1.12.0:
      + settings: Provide org.freedesktop.appearance.color-scheme key
      + settings: Handle org.gnome.desktop.a11y.interface schema
      + notification: Handle actions with targets properly
      + Enable settings and appchooser portals by default
      + Translation updates
    - Add pkgconfig(gsettings-desktop-schemas) BuildRequires and
      gsettings-desktop-schemas Requires and pass enable-appchooser and
      enable-settings to meson. This is needed for flatpak gtk apps
      running outside of gnome. See upstream issue/pull
      https://github.com/flatpak/xdg-desktop-portal-gtk/pull/362 and
      rh#2012315 for more info.
    -