CAPE TOWN, South Africa — Olympic champion runner Caster Semenya is ending a seven-year legal challenge against sex eligibility rules in track and field, her lawyers said Thursday, despite winning a ruling at the European Court of Human Rights in July that appeared to have reignited one of sports’ most contentious cases. Patrick Bracher, a lawyer for Semenya, said in an email to The Associated Press that they wouldn’t take her appeal back to the Swiss supreme court, which was an option and what