WASHINGTON (Reuters) – A U.N. report seen by Reuters says the Taliban and its allies are believed to have killed scores of former Afghan officials, security force members and people who worked with the international military contingent since the U.S.-led pullout. U.N. Secretary General Antonio Guterres’ report to the U.N. Security Council paints a picture of worsening living conditions for Afghanistan’s 39 million people despite an end of combat with the Taliban’s takeover in August. “An entire complex social and economic system is shutting down,” Guterres said. The report sounds the latest in…