BEIJING — A Chinese court sentenced a Canadian man to death on Monday in a drug smuggling case as tensions heightened between the two countries over Canada’s arrest last month of a top Chinese technology executive. In a sudden retrial, a Chinese court in northeastern Liaoning province announced that it had given Robert Lloyd Schellenberg the death penalty, reversing an earlier 2016 ruling that sentenced him to 15 years in prison. The court gave no indication that the penalty could be commuted, but Schellenberg’s fate is likely to be drawn into diplomatic negotiations over China’s demand for the release of Meng Wanzhou, chief financial officer of the Chinese telecommunications giant Huawei. Canadian Prime Minister Justin Trudeau strongly condemned Monday’s proceeding, suggesting that China was using its judicial system to retaliate against Canada.