The Library of Congress has agreed that “it's fun to stay at the Y.M.C.A.”The world’s largest library inducted the Village People’s gay anthem “Y.M.C.A” Wednesday to its National Recording Registry.The registry honors tracks and albums (at least 10 years old) that are “culturally, historically or aesthetically significant.”“Y.M.C.A,” a song that alludes to gay cruising culture at athletic centers, was penned in 1978 by Village People leader Victor Willis in collaboration with Jacques Morali, a