* Use XDG menu scheme from KDE, which is already implicitly introduced
by illogical-impulse-kde.
* Set XDG_MENU_PREFIX globally, so kbuildsycoca6 is automatically
invoked by /usr/bin/xdg-mime via the pacman hook. Consequently, the
manual call can (and should) be removed.
Check if dependencies were previously explicitly installed and set them
to implicit so they can be orphaned if no longer required by the new
meta packages which declare dependencies
