By Andrew Holleran Swimming’s governing body voted this weekend to prevent transgender athletes who transitioned after puberty from competing. FINA members voted 71.5% in favor of a policy that will require transgender swimmers to have completed their transition by age 12 in order to compete. Transgender athletes have been a focal point of debate in recent months, thanks in part to the success of Penn swimmer Lia Thomas. Thomas, who previously swam for the Penn men’s team, transitioned and began competing for the women’s team. The decision goes into effect on Monday. Thomas, who won a national…