gnome-network-displays: fix hardware acceleration

GNOME Network Displays is missing dependencies for GStreamer to make
hardware acceleration work. Add these missing dependencies.

pkgs/applications/networking/gnome-network-displays/default.nix

@@ -17,6 +17,7 @@
 , glib
 , networkmanager
 , libpulseaudio
+, pipewire
 }:
 
 stdenv.mkDerivation rec {
@@ -59,6 +60,8 @@ stdenv.mkDerivation rec {
     gst_all_1.gst-plugins-bad
     gst_all_1.gst-plugins-ugly
     gst_all_1.gst-rtsp-server
+    gst_all_1.gst-vaapi
+    pipewire
     networkmanager
     libpulseaudio
   ];