python312Packages.cffi: remove unnecessary Darwin patch

This is no longer required now that we use Apple’s `libffi`.

pkgs/development/python-modules/cffi/default.nix

@@ -24,20 +24,6 @@ else
       hash = "sha256-HDnGAWwyvEjdVFYZUOvWg24WcPKuRhKPZ89J54nFKCQ=";
     };
 
-    patches = [
-      #
-      # Trusts the libffi library inside of nixpkgs on Apple devices.
-      #
-      # Based on some analysis I did:
-      #
-      #   https://groups.google.com/g/python-cffi/c/xU0Usa8dvhk
-      #
-      # I believe that libffi already contains the code from Apple's fork that is
-      # deemed safe to trust in cffi.
-      #
-      ./darwin-use-libffi-closures.diff
-    ];
-
     nativeBuildInputs = [ pkg-config ];
 
     build-system = [ setuptools ];