SHANNEN Doherty claims in the last issue of Radar magazine, which just went bust, that she spends most of her time at home in California, reading or riding her horses. But she sure seems to enjoy the New York nightlife. At club Citrine for Radar's Print Is Dead party the other night, she caroused with hipsters and chain-smoked. When The Post's Justin Rocket Silverman asked if she was upset by the demise of Radar and other magazines, she cried out in frustration, "God, I don't know!" Then she and a friend moved on to the Eldridge, but she left quickly and was heard griping, "There are too many girls in here . . . too many model asses all over the place." A friend of Doherty told us, "She never complained about models and left to meet friends."