MEXICO CITY (Reuters) – A first flight carrying Venezuelan migrants voluntarily returning to their homeland from Mexico departed on Tuesday, according to two Mexican officials. Mexico is dealing with a major increase in the number of Venezuelans fleeing the country’s economic woes, due both to people arriving on its southern border and thousands more being expelled from the United States under a plan unveiled this month aimed at curbing migrant flows. The plane, operated by Venezuela’s state airline, left Mexico City’s Felipe Angeles International Airport destined for Caracas, the sources said…