gnome3.adwaita-icon-theme: reduce build parallelism

It was repeatedly failing to fork on our aarch64-darwin buildrers:
https://hydra.nixos.org/build/176633576#tabs-buildsteps

pkgs/desktops/gnome/core/adwaita-icon-theme/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, pkg-config, intltool, gnome
+{ lib, stdenv, fetchurl, fetchpatch, pkg-config, autoreconfHook, intltool, gnome
 , iconnamingutils, gtk3, gdk-pixbuf, librsvg, hicolor-icon-theme }:
 
 stdenv.mkDerivation rec {
@@ -10,12 +10,20 @@ stdenv.mkDerivation rec {
     sha256 = "XoW1rcje5maQD8rycbpxf33LnQoD2W2uCPnL0n4YseA=";
   };
 
+  patches = [
+    (fetchpatch {
+      name = "reduce-build-parallelism.patch";
+      url = "https://gitlab.gnome.org/vcunat/adwaita-icon-theme/-/commit/27edeca7927eb2247d7385fccb3f0fd7787471e6.patch";
+      sha256 = "vDWuvz5yRhtn9obTtHRp6J7gJpXDZz1cajyquPGw53I=";
+    })
+  ];
+
   # For convenience, we can specify adwaita-icon-theme only in packages
   propagatedBuildInputs = [ hicolor-icon-theme ];
 
   buildInputs = [ gdk-pixbuf librsvg ];
 
-  nativeBuildInputs = [ pkg-config intltool iconnamingutils gtk3 ];
+  nativeBuildInputs = [ pkg-config autoreconfHook intltool iconnamingutils gtk3 ];
 
   dontDropIconThemeCache = true;