By Karolos Grohmann, Julien Pretot and Gabrielle Tétrault-Farber BEIJING (Reuters) – Sport’s highest court on Monday cleared 15-year-old Russian figure skater Kamila Valieva to continue competing in the Beijing Winter Olympics, but the teenager’s doping charge remained a stain on the Games. No Olympic medals will be awarded at the women’s singles event on Thursday if Valieva finishes in the top three, with Games chiefs saying they would only present the prizes once her doping case was resolved. The Court of Arbitration for Sport (CAS) upheld an earlier decision by the Russian Anti-Doping Agenc…