WASHINGTON — A surge in Cuban and Nicaraguan arrivals at the U.S. border with Mexico in December led to the highest number of illegal border crossings recorded during any month of Joe Biden’s presidency, authorities said Friday. Cubans were stopped nearly 43,000 times in December, up 23% from November and more than quintuple the same period a year earlier. The number of Venezuelan arrivals remained far below September highs, when the South American country was the second-highest nationality at the border after Mexicans.