Dec. 7—Just when it looked like the Pittsburgh Steelers couldn’t set the bar any lower in terms of humiliating home defeats, they found a way to limbo under it Thursday night. Fresh off an upset loss to two-win Arizona four days earlier, the Steelers also were no match for the two-win New England Patriots, 21-18, at Acrisure Stadium. The Patriots, who had lost five in a row and had scored 13…