It's possible for casks to only run on certain os/arch
combinations but we don't check for them in the fetch and
audit commands.
At first, I tried to check if the macos version was satisfied
in a previous PR but that doesn't work correctly because
MacOSRequirement and ArchRequirement don't respect SimulateSystem.
Instead I'm just checking to see if the url stanza is defined
for each os/arch combination and skipping those casks where
it ends up being nil. This is kind of brute forcing it but
should work.
f4b15e95ac