cask/dsl/caveats: fix rosetta caveat printing

[bevanjkay]

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This is the third (and hopefully final) attempt to get the Rosetta caveat for Casks printing correctly.
The conditional in the if statement was changed in a previous PR, however this results in the caveat never printing when the architecture is simulated in audits (because the first half of the check returns first).

Homebrew::SimulateSystem.current_arch will be set correctly whether the system is being "simulated" or not. This mirrors the current logic in audit_rosetta.

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Unblocks Homebrew/homebrew-cask#181053