[3.9] bpo-34804: [doc] Rephrase section on side effects in functional.rst for clarity (GH-27989)#28763

ambv merged 1 commit intopython:3.9python/cpython:3.9from

miss-islington:backport-7af95a1-3.9miss-islington/cpython:backport-7af95a1-3.9Copy head branch name to clipboard