PHOENIX—Phil Mickelson stood on the 18th green at Phoenix Country Club, a wide smile across his face as he held yet another PGA Tour Champions trophy. Next to him was 64-year-old Bernhard Langer, grinning just as broadly as he hoisted the Charles Schwab Cup trophy at an age when most players are playing from the front tee boxes, not fighting for championships. One ceremony, two champions with vastly different styles. Mickelson birdied three of the final holes Sunday to win the season-ending Charles Schwab Cup Championship, and Langer held on to win his sixth PGA Tour Champions season points title. “It’s so fun for us to come back and play in front of everyone and then to come out on top here was a special week,” said Mickelson, who played collegiately at nearby Arizona State. “I want to congratulate Bernhard because he really is the gold standard for work ethic, …