Venerable Florent, a stalwart of the meat-packing district since 1987, is no longer open 24 hours a day. While it remains open around the clock on weekends, it now closes at 5 A.M. Mondays through Thursdays. But Florent is still one of the great late-night people-watching spots, especially at that transitional period early on weekend mornings, when the clientele of transvestites with hair in electric colors gives way to parents pushing strollers. The French menu now includes such Americana as crab cakes and vegetarian chili, but stick to the traditional bistro fare, like rillettes, steak frites and boudin noir, or to the breakfast menu.