WASHINGTON — The Supreme Court has agreed to hear an appeal from Starbucks in a dispute with the National Labor Relations Board over efforts by workers to unionize at a store in Memphis, Tennessee.The case has been among the most closely watched in the more than 2-year-old effort to unionize Starbucks’ company-owned U.S. stores.Starbucks fired seven employees in Memphis in February 2022, citing safety. The Seattle coffee giant said they violated company policy by reopening a store after closing time and …