By Zach Barnett The Wildcats enter 2023 having won two of their last 18 Big Ten games. Defensive coordinator Jim O’Neil, defensive line coach Marty Long and wide receivers coach Dennis Springer will not return at Northwestern, the program announced Tuesday. ESPN’s Adam Rittenberg first broke the news. O’Neil was in his second season leading the Wildcats defense, taking over for Mike Hankwitz, who retired in 2020 after 13 seasons manning the position. Most of O’Neil’s experience came at the NFL level — including coordinator stints in Cleveland and San Francisco — but he was a Northwestern GA …