[3.10] Fix typo in whatsnew 3.10.rst (GH-26854) (GH-28782)

Thanks for the fix @wiggin15 .
(cherry picked from commit 599c07006a636b0a6904008534118a9ba3daf726)


Co-authored-by: Arnon Yaari <wiggin15@yahoo.com>

Automerge-Triggered-By: GH:JulienPalard