After 104 years as the home of the third leg of the Triple Crown, the Belmont Stakes could fall victim to Albany's budget mess — or so says the New York Racing Association, which operates the Queens track where it's held. The group has a budget shortfall; it's currently campaigning for the enactment of a long-delayed plan to set up slot machines at Aqueduct, one of two other tracks it runs. If the legislature doesn't make this happen, says hardball-playing NYRA president Charles Hayward, the Belmont Stakes might not happen this year, either. "If we can't make payroll, we have to shut down. There is certainly a possibility that Belmont may not open and there will be no third leg of the Triple Crown,"