WASHINGTON—U.S. aviation regulators are forecasting nearly 313,000 flights over the seven-day Memorial Day holiday period, up 4.5 percent from 2022 and just below 2019 pre-pandemic levels. The Federal Aviation Administration (FAA) said the traditional seven-day kickoff to the busy U.S. summer travel season will surpass the 299,500 flights flown in the same period in 2022…