WASHINGTON, Oct 9 (Reuters) - Transportation Secretary Sean Duffy warned on Thursday that the government could dismiss air traffic controllers who repeatedly fail to show up for work during the government shutdown, saying a spike in absences is causing significant air disruptions. “If we have a continual small subset of controllers that don’t show up to work, and they’re the problem children ... if we have some on our staff that aren’t dedicated like we need, we’re going to let them go,” Duffy