[3.11] gh-88355: Fix backslashes in AF_PIPE (GH-96543) (#97854)

gh-88355: Fix backslashes in AF_PIPE (GH-96543)

Fix backslashes in AF_PIPE (GH-88355)

The correct syntax for AF_PIPE addresses is `\\.\pipe\blahblah`, not `\.\pipe{blahblah}`, but the syntax markup messed up the backslashes.
(cherry picked from commit ff28d8926de92d809e3b7f71d3e44672178ed11e)

Co-authored-by: cousteau <cousteaulecommandant@users.noreply.github.com>

Co-authored-by: cousteau <cousteaulecommandant@users.noreply.github.com>