A potential strike by Costco workers has been avoided after the Teamsters union reached a tentative contract agreement with the company, the union announced Saturday. The agreement, which still requires approval from union members, comes after 18,000 Teamsters at Costco—across California, Washington, Maryland, Virginia, New Jersey, and New York—voted to authorize a strike if a deal was not reached by midnight Friday. Details of the new three-year contract have not yet been disclosed…