The 81st Golden Globe Awards drew the biggest stars of stage and screen to the Beverly Hilton hotel Monday to see “Oppenheimer” celebrated while “Barbie” — the hit of the summer and the most nominated film — pretty much bombed. The event was hosted by comedian Jo Koy, who opened the show with a zinger about Robert De Niro, 79, becoming a dad again in May. The “Killers of the Flower Moon” actor was nominated for Best Performance by a Male Actor in a Supporting Role. That award went to “Oppenheimer” actor Robert Downey Jr. It was a sign of things to come. “Oppenheimer” won Best Motion Picture in…