Page Six has learned that Broadway superstar Laura Osnes has been let go from a Hamptons show because she refuses to be vaccinated against COVID-19. Osnes — who shot to fame when she won the talent search show “Grease: You’re the One That I Want!” in 2008, and has gone on to have a heavyweight Broadway career — was set to perform in front of a star-studded audience for a one-night production of “Crazy For You” at the Guild Hall in East Hampton on August 29. But the theater tells Page Six that it requires staff and performers to be...