[3.9] bpo-44219: Mention GH-28250 is a deadlock bugfix (GH-28261)#28275

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

miss-islington:backport-296b710-3.9miss-islington/cpython:backport-296b710-3.9Copy head branch name to clipboard