Jim Farley has been focusing on the US's shortage of "tktk" workersBloomberg/Getty ImagesFord's CEO continued his warning about a skilled workers shortage in the US in a coming podcast.His guest added, "People don't care about a shortage of plumbers until their toilet doesn't flush."Nearly half of manufacturers say hiring is a top challenge, industry data shows.Ford CEO Jim Farley says the US is in a "really vulnerable place" due to ongoing skil…