NEW YORK (AP) — With a winter storm blanketing a large swath of the country, Hollywood had its quietest weekend of the year at the box office. The Amazon MGM sci-fi thriller “Mercy” dethroned “Avatar: Fire and Ash” from the No. 1 spot with $11.2 million in North America, according to studio estimates Sunday. Hundreds of theaters were forced to close due to the storm, from Texas to Maine. More than 140 million Americans were under winter storm warnings, depressing moviegoing. But the weekend was