SPRINGFIELD — Operational shifts undertaken by the United States Postal Service in recent weeks, including spending cuts and equipment removal, are illegal, Illinois’ top lawyer and 13 other attorneys general argued in a federal lawsuit filed Tuesday.By terminating workers’ overtime, eliminating a number of mail sorting machines, removing several mailboxes and rescheduling the delivery of some late-day mail, Postmaster General Louis DeJoy is subverting the national election this year, the officials added …