WASHINGTON — The U.S. Supreme Court said today it won’t hear the Obama administration’s appeal of a lower court ruling that made it tougher to prosecute people for trading on leaked inside information.The justices let stand a decision by the federal appeals court in New York last year that threw out insider trading convictions of two high-profile hedge fund managers.The 2nd U.S. Circuit Court of Appeals overturned the convictions of Anthony Chiasson, of Manhattan and Todd Newman, of Needham, Mass., after …