SPRINGFIELD — A string of recent pension cases may have hinted that the state’s top court today was set to issue a weighty, constitutional rebuke of a law that forced Chicago Transit Authority retirees to pay for health benefits.But that’s not quite what happened in a 33-page majority opinion issued this morning.The Illinois Supreme Court did reverse a lower court’s preliminary decision to dismiss all claims brought by CTA workers, whose unions agreed to make them pay for health-care benefits after …