No game on Gog ever comes with Steam keys. It's agains their policy and interest. Sometimes the opposite occours, i.e. they let you redeem certain Steam games on Gog, but that is solely to attract new customers.

If you want a drm free + Steam version you could buy from the official site, or humble store which includes Gog and Steam keys (buying directly from the devs means they get a bit more money though).