By Makini Brice, David Morgan and Richard Cowan WASHINGTON (Reuters) – The U.S. Senate on Saturday inched toward passage of President Joe Biden’s $1.9 trillion coronavirus relief plan in an around-the-clock session that began on Friday involving nearly two dozen votes and hours of closed-door negotiations. Democrats, who narrowly control the chamber, agreed to scale back aid to the millions who have lost their jobs in the crisis. As Friday night turned to Saturday morning, they stuck together to turn back Republican attempts to modify the bill, which according to the Congressional Budget Offic…