U.S. Immigration and Customs Enforcement is retreating from a plan to use warehouses to hold up to 10,000 people on a single site, jettisoning a key piece of former Homeland Security Secretary Kristi Noem’s $38-billion plan to rapidly expand detention capacity this year. The federal government, which was sued by Michigan and a Detroit suburb, informed a judge Monday that a warehouse purchased in Romulus will be sold. Plans also are unraveling in Social Circle, Georgia, and the El Paso suburb of