Add more python package dependencies for qtile

Qtile cannot connect to dbus and cause applications to freeze when they attempt to send notifications.
For example, slack will completely freeze when a new message comes in after it attempts to send a notification.

This is caused by an inability to import dbus and pygobject3 as evidenced by this error in the logs
`WARNING libqtile manager.py:setup_eventloop():L240 importing dbus/gobject failed, dbus will not work.`

Also added the python packages dependencies mentioned here:
https://github.com/NixOS/nixpkgs/issues/45039
https://github.com/DavHau/mach-nix/issues/125

pkgs/applications/window-managers/qtile/default.nix

@@ -34,7 +34,18 @@ python37Packages.buildPythonApplication rec {
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ glib libxcb cairo pango python37Packages.xcffib ];
 
-  pythonPath = with python37Packages; [ xcffib cairocffi-xcffib setuptools setuptools_scm ]; 
+  pythonPath = with python37Packages; [
+    xcffib
+    cairocffi-xcffib
+    setuptools
+    setuptools_scm
+    dateutil
+    dbus-python
+    mpd2
+    psutil
+    pyxdg
+    pygobject3
+  ]; 
 
   postInstall = ''
     wrapProgram $out/bin/qtile \