PORTLAND, Ore. — In the aftermath of an active NBA trade deadline, the Pistons have started the process to shed contracts from their books to meet the required limit of 15 guaranteed players. Detroit is waiving Killian Hayes and veteran guard Joe Harris, league sources confirmed to The Detroit News on Thursday. The moves were first reported by The Athletic’s Shams Charania. Hayes, a 6-foot-5 guard, is being relieved of his duties in Detroit after what many would consider an underwhelming 3 1/2 years in the Motor City. He averaged 8.1 points, 2.9 rebounds and 5.9 assists in 210 games over the l…