Although supporters have joined critics in asking Bruce Ratner to downsize Atlantic Yards, the state is not pushing him to do so. Still, the Nets' owner may do it on his own to reap public relations benefits. Even without downsizing, the project has the support of key city and state officials, including those who killed the Jets' Stadium. The city has quietly added another $29 million to the $100 million already budgeted for the project while Ratner could get a P.R. boost for helping the Brooklyn Library.