MILAN — A few weeks ago, the New York Times published a story on doppelgängers, people unrelated by birth who share the genetic similarities of identical twins. Stop and think about that destabilising idea for a moment, how it challenges your faith in your own uniqueness as a human being. Somewhere, you have a twin. Maybe they are in Twinsburg, the place that Alessandro Michele offered up as the locale for Gucci’s Spring 2023 show on…