U.S. energy stocks including Chevron Corp CVX.N, Exxon Mobil Corp XOM.N and APA Corp APA.O led declines with falls between 0.6% and 2.1%. By Shreyashi Sanyal Oct 7 (Reuters) - U.S. stock index futures bounced on Thursday after a temporary truce in the debt-ceiling standoff in Congress relieved concerns of a possible government debt default, while a dip in oil prices eased worries of higher inflation. Top U.S. Senate Republican Mitch McConnell on Wednesday floated a plan to support an extension of the federal debt ceiling into December, potentially heading off a historic default.