kdelibs: remove setup hook

Fixes #17346.

The kdelibs setup hook unnecessarily propagates kdelibs into the system
environment, leading to KDE 4 services running in a KDE 5 session.

pkgs/desktops/kde-5/applications/kdelibs/default.nix

@@ -36,8 +36,6 @@ kdeApp {
     "-DKDE_DEFAULT_HOME=.kde"
   ];
 
-  setupHook = ./setup-hook.sh;
-
   meta = {
     platforms = lib.platforms.linux;
     homepage = "http://www.kde.org";

pkgs/desktops/kde-5/applications/kdelibs/setup-hook.sh

@@ -1,10 +0,0 @@
-addQt4Plugins() {
-  if [[ -d "$1/lib/qt4/plugins" ]]; then
-      propagatedUserEnvPkgs+=" $1"
-  fi
-
-  if [[ -d "$1/lib/kde4/plugins" ]]; then
-      propagatedUserEnvPkgs+=" $1"
-  fi
-}
-envHooks+=(addQt4Plugins)