Fix macos11 provision homebrew cask

What does this MR do?

1. Fixes an error while tapping homebrew/tap Cask ''/Applications/Emacs.app/Contents/Resources/man/man1/ebrowse.1.gz' is not a valid man page name' definition is invalid. by updating the brew cli to version 2.7.7
2. Moves away from homebrew_tap as that doesn't report errors when something fails, leaving us wondering. The shell commands work much better.

Why was this MR needed?

What's the best way to test this MR?

What are the relevant issue numbers?

Closes #83 (closed)