Tesla Inc. plans to remain working at its Shanghai plant in a so-called closed-loop formula, in which staff are shuttled to and from the factory and tested for COVID-19, until mid-June, other people said. familiar with the matter. even as the Chinese government moves to ease broader lockdown restrictions on the city. Thousands of employees at the electric carmaker sleep on the floor of Tesla’s factory south of Shanghai, in 12-hour shifts, six days a week, to restart production after a week-long pause due to the shutdown. Tesla needs to move staff into a dormitory and keep them in closed-loop…