REI’s unionized workers are calling for a boycott of the retailer’s biggest sale of the year after contract negotiations faltered — a move their employer said will distract from bargaining efforts. The workers recently approved a decision to call for a boycott of the retailer’s anniversary sale, which will run from May 15 to May 25. They’re asking the public not to shop at REI over that time period. Employees will continue working as normal, and unionized stores will remain open, Rich Smith, spokesperson for the United Food and Commercial Workers International Union Local 3000, said Friday. But about 70,000 REI members have pledged to heed the boycott during the sale, he added. The co-op denounced the call to action.…