Motivation for this change

I'm build a package which requires CommonCrypto >=60118.250.2 on osx-10.14.6, but it seems do a great impact on packages depanding on Libsystem-osx-10.12.

I doubt whether it's the right way. May I ask if there is another solution where I could use newer version CommonCrypto without updating Libsystem?

Things done

update CommonCrypto to 60118.250.2 on osx-10.14.6 .

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.