A staple of Celebrity Row at Knicks playoffs games had another NYC commitment Monday night — but it didn’t stop him from officially submitting his prediction for the series. Ben Stiller, whose fandom and presence at the Garden has been well-documented across their recent playoff runs, attended the Met Gala with his wife, Christine Taylor, as the Knicks hosted the 76ers in Game 1 of the Eastern Conference semifinals. As the couple walked up stairs and someone shouted about the Knicks, the actor and director helped up six fingers to signal his pick for the Knicks to advance after six games in a rematch of the thrilling first-round series two years ago. During that series, Stiller took a jab at Kelly Oubre Jr. on X after the 76ers guard called out Celebrity Row at the Garden by saying, “They’re gonna give celebrities those $100,000 [worth of] free tickets just to be there and not care about the game.” “Oh I think I care a lot more than you think that you thought I cared…” Stiller wrote on X at the time.…