desktop+{cinnamon,deepin,lxde,lxqt}: mark metapackages with @META suffix

pkg.in/lists/tagged/desktop+cinnamon

-cinnamon-regular
+cinnamon-minimal@META
+cinnamon-default@META
+cinnamon-regular@META
 installer-feature-xdg-user-dirs

pkg.in/lists/tagged/desktop+deepin

 # meta packages
-deepin-minimal
-deepin-default
-deepin-full
-deepin-regular
+deepin-minimal@META
+deepin-default@META
+deepin-full@META
+deepin-regular@META
 
 # polkit agent
 polkit-gnome

pkg.in/lists/tagged/desktop+lxde

-lxde
+lxde@META
 lxde-settings-lxdesktop
 gvfs-backend-mtp

pkg.in/lists/tagged/desktop+lxqt

 # metapackage
-lxqt-mini
-lxqt-regular
+lxqt-mini@META
+lxqt-regular@META
 
 # media-player
 mpv