ANN ARBOR, Mich. – After a pandemic-fueled boom, U.S. pizza sales appear to be headed back to earth. Domino’s and Papa John’s pizza chains both said Thursday that their same-store sales lost steam in the fourth quarter compared to the huge increases they saw earlier in 2020. Same-store sales are expected to continue seeing percentage declines well into this year. Pizza delivery remains popular, but diners’ choices are expanding, with more restaurants now offering delivery. Ann Arbor-based Domino’s said its same-store sales __ or sales at stores open at least a year __ were up 11% in the October-December period.