It was fun while it lasted. So much for that. Since the autumn of 1999 the ACC-Big Ten Challenge has been a fixture on the nonconference schedule, a three-day, post-Thanksgiving feast where the competing leagues take the measure of themselves and each other. The series has been around as long as most college seniors have been alive, so long that Michigan State’s Tom Izzo is the only man who’s led his teams into the high-level fray each of the 23 years it’s been in existence. But those orchestrated pairings, generally matching teams of supposedly comparable strength, are soon to be…