Just a few weeks ago, the easy assumption was that Jackson Arnold would leave Oklahoma for the NCAA transfer portal. But Arnold has got the starting role back, once again looking like the quarterback of the future in Norman. Brent Venables believes Arnold’s best game was on Saturday against Ole Miss, even if the Sooners were on the losing end. The future of Arnold has certainly changed, leaving for Venables to be asked about it. The head coach was pretty clear in his thought process, not believing No. 11 is leaving anytime soon. Venables believes Arnold is “built with the right stuff” and will…