A government agency does not have to face a class-action lawsuit over alleged mismanagement of the state’s college savings plan, known as a 529 plan.A panel of the 1st District Appellate Court ruled that the suit was barred by sovereign immunity and that the putative class did not have authority to pursue an action against the agency.Justice Aurelia Pucinski delivered the judgment of the court.Melissa Kay filed a putative class-action lawsuit against the Department of Central Management Services (DCMS), as surety of …