“Avatar: The Way of Water” stayed atop the U.K. and Ireland box office with £4.1 million ($5.1 million) in its fifth weekend for a running total of £63.5 million, according to numbers from Comscore. Universal’s “M3gan” and Disney’s “Empire of Light” opened strongly in second and third places with £2.3 million and £1.7 million respectively. […]