[3.13] gh-135965: Delete duplicate word in isolating-extensions howto (GH-135964) (#135978)

gh-135965: Delete duplicate word in isolating-extensions howto (GH-135964)

Change use use to use.
(cherry picked from commit ffb2a02f98d904505c8a82d8540c36dee4c67eed)

Co-authored-by: Weilin Du <108666168+LamentXU123@users.noreply.github.com>