TOKYO—Japan’s economy contracted at a 3.6 percent annual rate in July-September as a wave of coronavirus infections crimped travel and other activities, the government said Wednesday. The estimate for the last quarter, downgraded from an earlier report of a 3.0 percent contraction, reflected weakness in consumer spending and trade, the government said. In quarterly terms, the measure used for most economies, the economy contracted 0.9 percent, compared to the earlier estimate of a 0.8 percent contraction. The world’s third-largest economy was in a slump before the pandemic hit. Its recovery has been fitful due to precautions taken to curb COVID-19 infections. Troubles with supply chains, especially for computer chips used in autos, have also taken a toll. Japan’s latest big coronavirus outbreak, in the late summer, has receded for now with a sharp drop in cases. But it hit during the usually busy summer travel season, with calls for restricted …