Zo money, Zo problems. Mayor Zohran Mamdani’s hostile stance toward New York City businesses could jeopardize $12 billion in GDP — triggering a “death spiral” in the city’s finances as the young socialist blows off billionaire Ken Griffin moving jobs south, insiders warn. Dire data exclusively provided to The Post by the Partnership for New York City shows the coalition’s 300 corporate and financial firms that have created nearly a million jobs, as well as contribute $13.5 billion in taxes and