CANTON, MA—Touting the beverage as the perfect drink for those frigid, gray November mornings, Dunkin’ Donuts unveiled a new seasonal Rotting Jack-O’-Lantern Latte Thursday to celebrate the end of fall. “Containing our signature coffee mixed with an artisan blend of freshly ground dead leaves and decomposing pumpkin chunks, our Rotting Jack-O’-Lantern Latte wonderfully captures the feeling of autumn drawing to a desolate, miserable close, leaving only the long winter ahead,” said Dunkin’ Donuts spokesperson Carolyn Wiseman, adding that the latte comes topped with random pieces of stale, crushed-up Halloween candy that have been sitting at the bottom of a trick-or-treat…