adwaita-qt, qgnomeplatform: drop gnome team from maintainers

They are not really GNOME projects.

pkgs/data/themes/adwaita-qt/default.nix

···
     description = "A style to bend Qt applications to look like they belong into GNOME Shell";
     homepage = "https://github.com/FedoraQt/adwaita-qt";
     license = licenses.gpl2Plus;
-    maintainers = teams.gnome.members ++ (with maintainers; [ ]);
+    maintainers = with maintainers; [ ];
     platforms = platforms.all;
   };
 }

pkgs/development/libraries/qgnomeplatform/default.nix

···
     description = "QPlatformTheme for a better Qt application inclusion in GNOME";
     homepage = "https://github.com/FedoraQt/QGnomePlatform";
     license = licenses.lgpl21Plus;
-    maintainers = teams.gnome.members ++ (with maintainers; [ ]);
+    maintainers = with maintainers; [ ];
     platforms = platforms.linux;
   };
 }