sandbox: allow Rosetta 2 on Darwin
sandbox: allow Rosetta 2 on Darwin

This allows sandboxed x86_64-darwin builds on aarch64-darwin.

NixOS/nix,rycee/nix,NixOS/nix,rycee/nix,rycee/nix,NixOS/nix,NixOS/nix,rycee/nix,rycee/nix,NixOS/nix