COLUMBUS, Ohio — An Ohio law that singles out professional athletes and entertainers for taxation even when they’re in the state just a few days a year is unconstitutional, say several sport leagues including the NBA, NFL and NHL who want the state Supreme Court to strike the law down. At issue is an Ohio law that excludes entertainers or athletes from a ban on municipalities taxing people who perform services 12 or fewer days per year. The leagues say the law singles out professional athletes for less …