libxkbcommon: fix build on darwin with upstream patch

pkgs/development/libraries/libxkbcommon/default.nix

@@ -20,11 +20,13 @@ stdenv.mkDerivation rec {
     "-Dx-locale-root=${libX11.out}/share/X11/locale"
   ];
 
-  # Remove example program which fail on Darwin
-  postPatch = if stdenv.isDarwin then ''
-    substituteInPlace meson.build \
-      --replace "executable('rmlvo-to-keymap', 'test/rmlvo-to-keymap.c', dependencies: test_dep)" ""
-  '' else null;
+  patches = stdenv.lib.optionals stdenv.isDarwin [
+    # Fix build on darwin
+    (fetchpatch {
+      url = "https://github.com/xkbcommon/libxkbcommon/commit/32d178b50fe0da05e51e4fe8903c84371d133331.patch";
+      sha256 = "1wqdjla8hmgdqr8xc2manw363sxrqqsn3s8bd397h3cd7fj3hh1v";
+    })
+  ];
 
   doCheck = false; # fails, needs unicode locale