WASHINGTON — Members of Congress promised that this time they’d successfully reform policing, amid the national furor over George Floyd’s 2020 murder and the conviction of the officer responsible for his death. President Biden urged them to bring a plan to his desk by the one-year anniversary. That deadline was Tuesday, and members haven’t reached a deal. A major sticking point is qualified immunity, or more specifically, whether officers can be sued for violating people’s civil rights. Although this immunity was created by the courts, Congress can pass a law revoking or modifying it. The trouble has long been agreeing on how.