bpo-44713: [doc fix]: typo in subprocess.rst (GH-27297) (GH-27298)

This fixes a small typo. The code fragment should not be quoted. Thank you
@merwok for the feedback.
(cherry picked from commit 7d25254cf0763b62f4c4a3019e56385cab597b9f)

Co-authored-by: Jack DeVries <58614260+jdevries3133@users.noreply.github.com>
1 file changed