Open this photo in gallery: London Mayoral Labour Party candidate Sadiq Khan and his wife Saadiya Ahmed pose for the media as they arrive to vote in London, May 2, 2024.Kin Cheung/The Associated Press London Mayor Sadiq Khan has a lot of cleaning up to do. Khan, who made history Saturday by becoming the city’s first mayor elected to a third term, has pledged to make the River Thames swimmable. It wasn’t a top campaign issue but it’s an audacious goal considering the waterway was declared biologically dead not long before his birth in the city in 1970 and flows...