[3.13] gh-98552: Revert (unneeded, already done elsewhere) "flush std streams in...

[3.13] gh-98552: Revert (unneeded, already done elsewhere) "flush std streams in the multiprocessing forkserver before fork (GH-141849)" (GH-141871) (#141873)

gh-98552: Revert (unneeded, already done elsewhere) "flush std streams in the multiprocessing forkserver before fork (GH-141849)" (GH-141871)

Revert (unneeded, already done elsewhere) "gh-98552: flush std streams in the multiprocessing forkserver before fork (GH-141849)"

This reverts commit 58badb1711e12b6e8b5240ab96cdd01b95012de7.
(cherry picked from commit 614a28b3da1c898f29c34c14f59bf2d496dbd31d)

Co-authored-by: Gregory P. Smith <68491+gpshead@users.noreply.github.com>