gnome: rename from gnome3

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

pkgs/desktops/gnome/extensions/material-shell/default.nix

@@ -0,0 +1,35 @@
+{ stdenv, lib, fetchFromGitHub, gnome }:
+
+stdenv.mkDerivation rec {
+  pname = "gnome-shell-extension-material-shell";
+  version = "12";
+
+  src = fetchFromGitHub {
+    owner = "material-shell";
+    repo = "material-shell";
+    rev = version;
+    sha256 = "0ikrh70drwr0pqjcdz7l1ky8xllpnk7myprjd4s61nqkx9j2iz44";
+  };
+
+  # This package has a Makefile, but it's used for building a zip for
+  # publication to extensions.gnome.org. Disable the build phase so
+  # installing doesn't build an unnecessary release.
+  dontBuild = true;
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out/share/gnome-shell/extensions/${uuid}
+    cp -r * $out/share/gnome-shell/extensions/${uuid}/
+    runHook postInstall
+  '';
+
+  uuid = "material-shell@papyelgringo";
+
+  meta = with lib; {
+    description = "A modern desktop interface for Linux";
+    license = licenses.mit;
+    maintainers = with maintainers; [ benley ];
+    homepage = "https://github.com/material-shell/material-shell";
+    platforms = gnome.gnome-shell.meta.platforms;
+  };
+}