BENTON, Ark. — The giant retailer Walmart will close its stores on Thanksgiving Day for the first time in more than 30 years. The decision covers 4,700 U.S. stores, including one in Winona. Some industry experts said the decision was triggered by concern about the frenzy of shoppers lured by traditional Thanksgiving discounts during the coronavirus pandemic. Another trigger, experts say, has been continuing pressure from labor advocates for workers to be home with their families for the holiday. Meanwhile, Walmart’s Sam’s Club chain, which historically has closed on Thanksgiving, will do so again. In making the announcement, Walmart chief executive John Furner acknowledged that employees will miss a day’s pay but also noted too that the company has is $428 million for special bonuses to employees for working through the pandemic. Hourly workers will receive a bonus of $300 and part-time and temporary workers will get $150, he said. The new bonuses are the third this year.