SPRINGFIELD — The state’s top lawyer may want another shot to prove sweeping state pension changes are legal. Attorney General Lisa M. Madigan has requested more time to ask the U.S. Supreme Court to take up the case, citing her deputies’ workload on other cases. Her request was sent last week to Justice Elena Kagan and asks the high court to give the state until Sept. 10 to file a certiorari petition. The deadline now is Thursday, 90 days after the Illinois Supreme Court struck down the pension law for violating a state …