SPRINGFIELD — The state’s top court has upheld Drew Peterson’s conviction for the killing of his third wife, Kathleen Savio.In 40 pages, the Illinois Supreme Court unanimously dispensed with each of the ex-Bolingbrook police sergeant’s complaints about a faulty trial in 2012 that led to a 38-year prison sentence.Peterson made national headlines in 2007 after his fourth wife Stacy disappeared. The incident led to new questions about Savio’s death, which was initially ruled an accidental bathtub …