nixos/systemd: missing a few units for KDE to use systemd

nixos/modules/system/boot/systemd.nix

···
       "timers.target.wants"
     ];
 
-  upstreamUserUnits =
-    [ "basic.target"
+    upstreamUserUnits = [
+      "app.slice"
+      "background.slice"
+      "basic.target"
       "bluetooth.target"
       "default.target"
       "exit.target"
···
       "graphical-session.target"
       "paths.target"
       "printer.target"
+      "session.slice"
       "shutdown.target"
       "smartcard.target"
       "sockets.target"
···
       "systemd-tmpfiles-clean.timer"
       "systemd-tmpfiles-setup.service"
       "timers.target"
+      "xdg-desktop-autostart.target"
     ];
 
   makeJobScript = name: text: