NEW YORK — It took more than 20 years, but the eyewitnesses to Jam Master Jay’s 2002 murder pushed past their fear to take the stand about his killers — and they were clear about who they saw. That’s the argument Assistant U.S. Attorney Artie McConnell made to close out the trial of two men charged with murdering the Run-DMC icon, real name Jason Mizell, in his Queens music studio over a drug deal in 2002. “They were afraid. They didn’t want to get involved. They moved away from New York to get away,” McConnell said in his closing argument in Brooklyn Federal Court Tuesday. “I will concede tha…