Washington — U.S. Olympic athletes have lost faith in the World Anti-Doping Agency to rid their sports of cheaters ahead of next month’s Summer Games in Paris, two former gold medalists said Tuesday in prepared testimony before a House subcommittee. The comments by Michael Phelps and Allison Schmitt followed revelations that 23 Chinese swimmers had tested positive for a banned heart medication ahead of the Tokyo Olympics in 2021 but were allowed by WADA to compete.