Fix casks with `depends_on` that reference pre-Mavericks

If you get an error like Error: Cask 'hex-fiend-beta' definition is invalid: invalid 'depends_on macos' value: ":lion", where hex-fiend-beta can be any cask name and :lion any macOS release name, run the following command:

/usr/bin/find "$(brew --prefix)/Caskroom/"*'/.metadata' -type f -name '*.rb' -print0 | /usr/bin/xargs -0 /usr/bin/perl -i -pe 's/depends_on macos: \[.*?\]//gsm;s/depends_on macos: .*//g'

This strips out all depends_on macos references from installed casks. It’s a blunt instrument – you’re editing Homebrew’s metadata files directly – but it gets things working again.

The issue comes from casks that declare support for macOS versions older than Mavericks (10.9), which Homebrew no longer recognises. Removing the constraint lets them install on newer systems.