BEIJING—China’s economy grew at the slowest pace in a year in the third quarter, hurt by power shortages, supply bottlenecks, and sporadic COVID-19 outbreaks, raising heat on policymakers amid rising jitters over the property sector. Data released on Monday showed gross domestic product (GDP) grew 4.9 percent in July-September, the weakest pace since the third quarter of 2020 and slowing from 7.9 percent in the second quarter. That marked a further deceleration from the 18.3 percent expansion in the first quarter, when the year-on-year growth rate was heavily flattered by the very low comparison seen during the COVID-induced slump of early 2020. A Reuters poll of analysts had expected GDP to rise 5.2 percent in the third quarter. On a quarterly basis, growth eased to 0.2 percent in July-September from a downwardly revised 1.2 percent in the second quarter, the data showed. The world’s second-largest economy has rebounded from the pandemic …