gnome3: remove version attribute

It was used by some themes in the past, but it broke them whenever GNOME
was updated, so it should not be used anymore.

pkgs/desktops/gnome-3/core/gnome-user-docs/default.nix

@@ -17,7 +17,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ gnome3.yelp itstool libxml2 intltool ];
 
   meta = with stdenv.lib; {
-    homepage = "https://help.gnome.org/users/gnome-help/${gnome3.version}";
+    homepage = https://help.gnome.org/users/gnome-help/;
     description = "User and system administration help for the GNOME desktop";
     maintainers = gnome3.maintainers;
     license = licenses.cc-by-30;

pkgs/desktops/gnome-3/default.nix

@@ -7,7 +7,6 @@ lib.makeScope pkgs.newScope (self: with self; {
 
   updateScript = callPackage ./update.nix { };
 
-  version = "3.26";
   maintainers = with pkgs.lib.maintainers; [ lethalman jtojnar ];
 
   corePackages = with gnome3; [

pkgs/misc/themes/materia-theme/default.nix

@@ -23,7 +23,7 @@ stdenv.mkDerivation rec {
     patchShebangs install.sh
     sed -i install.sh \
       -e "s|if .*which gnome-shell.*;|if true;|" \
-      -e "s|CURRENT_GS_VERSION=.*$|CURRENT_GS_VERSION=${gnome3.version}|"
+      -e "s|CURRENT_GS_VERSION=.*$|CURRENT_GS_VERSION=${stdenv.lib.versions.majorMinor gnome3.gnome-shell.version}|"
     mkdir -p $out/share/themes
     ./install.sh --dest $out/share/themes
     rm $out/share/themes/*/COPYING