Cleanup monkeypatching bottles.

Make use of the new Homebrew bottle monkey patching module that's being added in https://github.com/Homebrew/homebrew/pull/27890 to make the Boxen bottle handling more robust. Long-term we/you should really move to using proper Homebrew bottles (with checksums and SSL) but this
should at least stop things getting broken periodically.

This may need cleanup/fixing once the Homebrew PR lands so it's mainly here now to get some early eyes on the approach. I'm aware this may be somewhat controversial so I'm open to other approaches.