State lawyers are trying to dissuade the nation’s top court from weighing in on an appeal from Cook County’s public defender.The attorney general’s office has filed a brief in opposition to Amy P. Campanelli’s claims that forcing her and her office to represent multiple defendants in one case is a Sixth Amendment violation.In a 20-page brief, lawyers from Lisa M. Madigan’s office have argued that the U.S. Supreme Court should avoid the case because it doesn’t technically involve the U.S. …