Canada said on Monday it was expelling a Chinese diplomat amid reports he had been intimidating and gathering information on a Canadian lawmaker who had been critical of Beijing’s treatment of its Uyghur Muslim minority, a decision likely to increase tensions between Beijing and Ottawa. Mélanie Joly, Canada’s foreign minister, said in a statement that the diplomat, Zhao Wei, had been declared “persona non grata.” Ms. Joly said the decision has been taken “after careful consideration of all factors at play.” “Diplomats in Canada have been warned that if they…