The dough must go on. A Staten Island pizzeria owner spent months testing dough recipes, firing up more than 500 pies, to find one his customers couldn’t distinguish from the original — all to get ahead of a New York State ban on a cancer-linked flour additive used in pizza and bagels now awaiting Gov. Kathy Hochul’s signature. John Caggiano, 54, who’s run Il Forno in Pleasant Plains with his wife, Gwen, 50, for more than two decades, pulled potassium bromate from his kitchen after reading