NEW YORK — Snakes are not a typical concern for most New Yorkers. Yet this fall, Julisa Rodriguez nearly tripped over one in her backyard. “I almost passed out,” said Rodriguez, 38, a stay-at-home mother of two. The snake’s appearance had followed a rat infestation, a septic tank leak, groundwater pooling in her living room and mushroomlike spores growing on her walls. None of this was surprising, she said, when you live in the Hole. Sitting along the border between Brooklyn and Queens, the Hole