ORLANDO, Fla. — Delaware officials were preparing Tuesday for a possible unannounced wave of migrants sent by Florida Gov. Ron DeSantis to land at an airport less than 20 miles from the vacation home of President Biden near Rehoboth Beach. One of two planes that flew 48 mostly Venezuelan migrants from Texas to Martha’s Vineyard last week was scheduled to leave San Antonio on Tuesday to Delaware Coastal Airport in Georgetown, Delaware, according to FlightAware, an aviation-tracking website. But as of early afternoon, the status of the flight was unknown. “Our teams at (Delaware Emergency Manage…