Marking the end of an era, New York City on Monday removed the last of its storied payphone booths, which have fallen victim to the ubiquity of free Wi-fi and cell phones in recent years. But Superman fans can take comfort in the fact that Manhattan will keep four of the defunct booths, made famous as the impromptu changing rooms for journalist Clark Kent as he transformed into the Man of Steel. Over the decades, the phone booths have featured widely in pop culture, from comic books to Hollywood blockbusters and TV shows. That ended Monday morning, when, in front of assembled media, Manhattan …