pkg-stage.sh: kde5 -> kde

The "kde5" package no longer exists; KDE goes to 6.

Note: Depending on the size of 13.5-BETA3 DVD images, KDE might end
up being removed from this list in the near future.

With hat:	re@
Approved by:	re (cperciva)
MFC after:	30 seconds
Sponsored by:	Amazon

(cherry picked from commit 0d7b98c06c)
(cherry picked from commit 4ddbb7945c)

release/scripts/pkg-stage.sh

@@ -28,7 +28,7 @@ sysutils/tmux
 www/firefox
 www/links
 x11/gnome
-x11/kde5
+x11/kde
 x11/sddm
 x11/xorg
 x11-wm/sway"