audit: Move patch checks from brew audit to rubocop

[FTLam11]

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There are some TODOs marked in https://github.com/Homebrew/brew/pull/7371/files for migrating audit checks to rubocop. This PR moves two patch checks to the patches cop. There is an open issue #7392.

[MikeMcQuaid]

Great work! Thanks again @FTLam11, you rock.