bazel: cctools runtime dependency on darwin (#66724)

The bazel build patches paths like `/usr/bin/install_name_tool` to refer
to `${cctools}/bin/install_name_tool` instead. If the corresponding
runtime dependency is not denoted, then darwin users can encounter "file
not found" errors, e.g. when they fetch bazel from a binary cache and
don't have `cctools` in their own nix store.