PHILADELPHIA — OG Anunoby’s absence left massive shoes to fill. The Knicks were fully up for the challenge. They got help from the starting lineup, as Mikal Bridges finished with 23 points — his second-highest output of the postseason. They got help from the bench, as Landry Shamet — who had been out of the rotation previously — stepped up with 15 points and helped close the game. There were bigger responsibilities up-and-down the roster. And the Knicks fulfilled them en route to their 108-94 Game 3 win over the 76ers on Friday night at Xfinity Mobile Arena, which gave them a 3-0 series lead. “It was definitely a team effort,” Jalen Brunson said. “Obviously, we want everyone back healthy. But it was important for everyone to step up and have the right mindset. To do whatever you gotta do to win.” Friday was too soon for Anunoby , who was out with the right hamstring strain he suffered in Game 2.…