“ Accordingly, the judgment of the District Court is vacated as moot insofar as it concerns the issues here appealed, namely, whether N.Y.Laws 1964, cc. 977-978, 979, 981, are violative of the Equal Protection Clause of the Fourteenth Amendment to the Constitution, and whether the District Court was entitled to rely on provisions of the New York Constitution possibly affected by the action of this Court in WMCA, Inc. ”