Ice skaters will have to be at least 17 to take part in senior competitions after the sport’s governing body voted Tuesday to raise the minimum age from 15. The decision by the International Skating Union (ISU) congress in Phuket, Thailand, came months after a Beijing Winter Olympics drugs scandal involving then-15-year-old Russian figure skater Kamila Valieva. “It’s a very historic decision,” ISU president Jan Dijkema said, after 100 countries voted to support the measure, with only 16 opposed. Valieva failed a pre-Games drugs test but was allowed to compete and then broke down after falling …