Scratch Manny Acta off any list of potential Met managers after this season. It’s not because the ex-Mets coach, current manager of the Nationals and close friend of GM Omar Minaya and VP Tony Bernazard wouldn’t be interested. No, it’s because Acta is under contract through 2009 and Nationals GM Jim Bowden tells The Washington Post that permission would be denied to the Mets if they called.