Theatergoers at the Tony-winning show “The Nance” on Wednesday night were left doing double takes when two “Star Trek” favorites beamed in together. Zachary Quinto and Leonard Nimoy — who both play Spock in J.J. Abrams’ version of the sci-fi epic — “arrived in tandem to catch Nathan Lane’s performance at the Lyceum Theatre,” said one gobsmacked spy. The sighting had any Trekkie fans drooling, and the actors appeared backstage after the show to tell Lane and the rest of the cast to live long and prosper.