Service interruption via quadratic whitespace trimming

Regular expression denial of service in Axios 0.21.1 and earlier allows remote attackers to interrupt applications via crafted strings. The exported utils.trim helper applies an end-anchored \s* expression that repeatedly backtracks across long whitespace runs when the final character is not whitespace. Exposure requires a consuming application to pass attacker-controlled text, including parsed HTTP response headers, through the helper; successful requests consume excessive CPU and can stall that application.