Europe's STOXX 600 index closed above a three-month high on Thursday, as investors cheered U.S. Federal Reserve Chair Jerome Powell's hints of smaller interest rate hikes and China's decision to soften its tone on strict COVID-19 restrictions. The pan-European STOXX 600 index climbed 0.9% to hit its highest since Aug 17. It gained 6.8% in November to log its best month since July. Technology stocks helped boost the index, advancing 2.9%, with traders pointing to some support from U.S. peer Salesforce raising its profit forecast. Tech shares also were buoyed by a drop in euro zone yields, following U.S. Treasuries,…