chez-racket: Fix signing on Darwin (Thanks @Steven0351!)

pkgs/development/compilers/chez-racket/shared.nix

···
     export LZ4="$(find ${lz4.out}/lib -type f | sort | head -n1)"
   '';
 
-  nativeBuildInputs = lib.optional stdenv.isDarwin darwin.cctools;
+  nativeBuildInputs = lib.optionals stdenv.isDarwin (with darwin; [ cctools autoSignDarwinBinariesHook ]);
   buildInputs = [ ncurses libX11 zlib lz4 ]
     ++ lib.optional stdenv.isDarwin libiconv;