Canada’s Shopify Inc. on Wednesday forecast a slowing pace in first-half revenue growth, indicating the e-commerce boom seen during the pandemic is cooling as retailers shift their focus back to brick-and-mortar stores from online. U.S.-listed shares of the company were down about 6 percent in trading before the bell. Ottawa-based Shopify—which helps merchants set up online stores through subscription-based software tools, while offering services such as shipping to payments—benefited during the pandemic as businesses quickly moved online to ride a boom in e-commerce. “We believe that the COVID-triggered acceleration of e-commerce that spilled into the first half of 2021 in the form of lockdowns and government stimulus will be absent from 2022, and there is caution around inflation and consumer spend near term,” the company said in a statement. It expects revenue growth for 2022 to be lower than the 57 percent rise recorded in 2021. For the fourth quarter …