AUSTIN, Texas — The U.S. Supreme Court extended a pause Tuesday on a Texas law that would allow police to arrest migrants accused of crossing into the country illegally as federal and state officials prepare for a showdown over immigration enforcement authority.Justice Samuel Alito’s order extending the hold on the law until Monday came a day before the previous hold was set to expire. The extension gives the court an extra week to consider what opponents have called the most extreme attempt by a state to …