WASHINGTON, May 2 - Bankrupt low-cost airline Spirit Airlines ceased operations on Saturday, becoming the first airline failure tied to the ongoing Iran war, after it was unable to win creditor backing for a proposed U.S. government rescue package. The shutdown marks the first airline collapse linked to the sharp rise in jet fuel prices during the two-month conflict, a development that will eliminate thousands of jobs. The failure also represents a setback for President Donald Trump, who had