The 81st Venice International Film Festival starts on Wednesday with 21 international films vying for the top prize, the Golden Lion. The gala event is scheduled to start at 7 pm (1700 GMT), with Italian actress Sveva Alviti hosting the evening. Tim Burton’s “Beetlejuice Beetlejuice”, featuring Winona Ryder and Michael Keaton, will be shown at the opening. The contenders for the Golden Lion range from star-studded films to promising arthouse cinema. Lady Gaga and Joaquin Phoenix star in Todd Phillips’ “Joker” sequel, while Nicole Kidman is a businesswoman who begins an affair with a young inte…