debian,fedora: drop gnome-packagekit from dependencies

We don't use it currently - xterm with console updater is used by
default.

debian/control

@@ -59,7 +59,6 @@ Depends:
     ${misc:Depends}
 Recommends:
     cups,
-    gnome-packagekit,
     gnome-terminal,
     gnome-themes-standard,
     haveged,

rpm_spec/core-vm.spec

@@ -139,10 +139,6 @@ Requires:   pygobject3-base
 Requires:   dbus-python
 # for qubes-session-autostart, xdg-icon
 Requires:   pyxdg
-%if %{fedora} >= 20
-# gpk-update-viewer required by qubes-manager
-Requires:   gnome-packagekit-updater
-%endif
 Requires:   ImageMagick
 Requires:   librsvg2-tools
 Requires:   fakeroot