blender: mark broken on darwin

Has been broken likely since edcd3849a6.

First failing Hydra: https://hydra.nixos.org/build/211894618

Notes from attempt to fix:

- The initial breakage may be easy to fix, but the upgrade to 3.4 added
  a lot more hurdles
- The patch fails to apply, but is trivially naïvely fixable
- At least some of the existing darwin-specific substituteInPlace no
  longer find anything
- When building with naïve fix for patch, fails with:
   > Could NOT find USD (missing: USD_LIBRARY USD_INCLUDE_DIR)
  for reasons that are not clear to me

The package has been broken for two months and no open issues, so
marking as broken as it’s not going to fix itself and if there is will
to fix it, someone can. For now, leaving the darwin conditionals in
place so not as to make a would-be-fixer’s job harder.

pkgs/applications/misc/blender/default.nix

@@ -181,6 +181,7 @@ stdenv.mkDerivation rec {
     # OptiX, enabled with cudaSupport, is non-free.
     license = with licenses; [ gpl2Plus ] ++ optional cudaSupport unfree;
     platforms = [ "x86_64-linux" "x86_64-darwin" "aarch64-linux" ];
+    broken = stdenv.isDarwin;
     maintainers = with maintainers; [ goibhniu veprbl ];
   };
 }