Allow using dashes (`-`) in tap names

This allows for tap repositories to contain dashes anywhere in name not only in
the `homebrew-` prefix.

This bring it on par with `TestBot.HOMEBREW_TAP_REGEX` (see
https://github.com/Homebrew/brew/blob/110b93e/Library/Homebrew/test_bot.rb#L24)
and `Bundle.Dsl.Entry.HOMEBREW_TAP_ARGS_REGEX` (see
https://github.com/Homebrew/brew/blob/110b93e/Library/Homebrew/bundle/dsl.rb#L114).

I have stumbled upon it when wanted to add my formulae to
`runtime_cpu_detection_allowlist.json` in `pkryger/homebrew-emacsmacport-exp`
tap, and `brew audit --strict` has been not accepting my exceptions (see
https://github.com/orgs/Homebrew/discussions/6656).