cargo-vendor: fix build on Darwin

This is supposedly fixing the build of the cargo crate on Drawin [1].

[1] https://github.com/NixOS/nixpkgs/pull/57017#pullrequestreview-228868016

pkgs/build-support/rust/default-crate-overrides.nix

@@ -16,7 +16,8 @@ in
   };
 
   cargo-vendor = attrs: {
-    buildInputs = [ openssl zlib curl ];
+    buildInputs = [ openssl zlib curl ]
+      ++ stdenv.lib.optionals stdenv.isDarwin [ Security ];
   };
 
   libz-sys = attrs: {