binaries: Add Brewfile for macOS

While there is a homebrew module for Ansible, it comes with the caveat that "homebrew must already be installed on the target system" and implementing an automatic installation via a git-clone does not work easily because Homebrew checks out a stable branch without a remote equivalent. As we only need to install a small number of packages via Homebrew on macOS, it is instead easier to just maintain a Brewfile.