France’s highest court has blocked a key part of a contentious farming law that would have brought back a banned pesticide. The court said Thursday that the measure failed to protect the environment and future generations. The rest of the law was allowed to stand. The bill was passed in early July. It aimed to loosen rules for farmers and fast-track projects like water storage. It was backed by the government and major farming unions. But it met fierce opposition from scientists, health experts and green groups.