John Tiffany, the celebrated British director of the current Broadway hit “Once,” will return to the American Repertory Theater next year to stage “The Glass Menagerie,” making it the first Tennessee Williams production ever by the Cambridge theater. The ART’s 2012-13 subscription season will also include Taylor Mac’s “The Lily’s Revenge,” Banana Bag and Bodice’s “Beowulf — A Thousand Years of Baggage,” and the previously announced “Pippin” and “Marie Antoinette.”