[3.9] gh-97005: Update libexpat from 2.4.7 to 2.4.9 (gh-97006) (gh-97012)

gh-97005: Update libexpat from 2.4.7 to 2.4.9 (gh-97006)

Co-authored-by: Gregory P. Smith [Google] <greg@krypto.org>
(cherry picked from commit 10e3d398)

Co-authored-by: Dong-hee Na <donghee.na@python.org>
Co-authored-by: Ned Deily <nad@python.org>