Former President Joe Biden was spotted dining out in Northern Virginia on Sunday with his old Pentagon chief, Lloyd Austin.  Biden, 82, was flanked by Secret Service agents as he slowly made his way through the outdoor patio of Carbonara, an Italian restaurant in deep-blue Arlington, Va., video posted on social media showed.  Some surprised diners gasped and applauded when they saw the former president amble into the restaurant.  Biden, who was seated across from Austin and an unidentified