WASHINGTON (Reuters) – President Joe Biden named businessman and former COVID-19 response coordinator Jeff Zients to become his second White House chief of staff on Friday, replacing Ron Klain, who is departing the administration after two years on the job. Zients, a wealthy Democratic government official with a business management background, takes the helm as the U.S. government rolls out trillions in spending related to Biden-backed bills, and the president, 80, gears up to run for a second term. WHO IS JEFF ZIENTS? Zients, who served as co-chair for Biden’s transition process after his 202…