gnome: rename from gnome3

Since GNOME version is now 40, it no longer makes sense to use the old attribute name.

pkgs/games/gscrabble/default.nix

@@ -1,6 +1,6 @@
 { lib, buildPythonApplication, fetchFromGitHub
 , gtk3, wrapGAppsHook, gst_all_1, gobject-introspection
-, python3Packages, gnome3 }:
+, python3Packages, gnome }:
 
 buildPythonApplication {
   pname = "gscrabble";
@@ -19,7 +19,7 @@ buildPythonApplication {
 
   buildInputs = with gst_all_1; [
     gst-plugins-base gst-plugins-good gst-plugins-ugly gst-plugins-bad
-    gnome3.adwaita-icon-theme gtk3 gobject-introspection
+    gnome.adwaita-icon-theme gtk3 gobject-introspection
   ];
 
   propagatedBuildInputs = with python3Packages; [ gst-python pygobject3 ];

pkgs/games/megaglest/default.nix

@@ -1,6 +1,6 @@
 { lib, stdenv, cmake, pkg-config, git, curl, SDL2, xercesc, openal, lua, libvlc
 , libjpeg, wxGTK, cppunit, ftgl, glew, libogg, libvorbis, buildEnv, libpng
-, fontconfig, freetype, xorg, makeWrapper, bash, which, gnome3, libGLU, glib
+, fontconfig, freetype, xorg, makeWrapper, bash, which, gnome, libGLU, glib
 , fetchFromGitHub
 }:
 let
@@ -13,7 +13,7 @@ let
   };
   path-env = buildEnv {
     name = "megaglest-path-env";
-    paths = [ bash which gnome3.zenity ];
+    paths = [ bash which gnome.zenity ];
   };
 in
 stdenv.mkDerivation {

pkgs/games/openra/default.nix

@@ -25,7 +25,7 @@ let
     lua = pkgs.lua5_1;
     # It is not necessary to run the game, but it is nicer to be given an error dialog in the case of failure,
     # rather than having to look to the logs why it is not starting.
-    inherit (pkgs.gnome3) zenity;
+    inherit (pkgs.gnome) zenity;
   });
 
   /*  Building a set of engines or mods requires some dependencies as well,

pkgs/games/openra/packages.nix

@@ -15,7 +15,7 @@ let
     lua = pkgs.lua5_1;
     # It is not necessary to run the game, but it is nicer to be given an error dialog in the case of failure,
     # rather than having to look to the logs why it is not starting.
-    inherit (pkgs.gnome3) zenity;
+    inherit (pkgs.gnome) zenity;
   });
 
   /*  Building a set of engines or mods requires some dependencies as well,

pkgs/games/steam/fhsenv.nix

@@ -85,7 +85,7 @@ in buildFHSUserEnv rec {
   targetPkgs = pkgs: with pkgs; [
     steamPackages.steam
     # License agreement
-    gnome3.zenity
+    gnome.zenity
   ] ++ commonTargetPkgs pkgs;
 
   multiPkgs = pkgs: with pkgs; [