gnomeExtensions.gsconnect: Use GTK 4 variant of e-d-s

It does not really matter since gsconnect does not use libedataserverui,
only EBookContacts and EDataServer typelibs but we are aiming for
not using gtk3 variant of e-d-s in GNOME closure.

pkgs/desktops/gnome/extensions/gsconnect/default.nix

···
 , gtk3
 , openssh
 , gnome
+, evolution-data-server-gtk4
 , gjs
 , nixosTests
 }:
···
     gtk3
     gsound
     gjs # for running daemon
-    gnome.evolution-data-server # for libebook-contacts typelib
+    evolution-data-server-gtk4 # for libebook-contacts typelib
   ];
 
   mesonFlags = [