[3.13] gh-108219: Add credits to the free-threading entry in What's New (GH-123802) (#123847)

gh-108219: Add credits to the free-threading entry in What's New (GH-123802)
(cherry picked from commit aa3f11f80a644dac7184e8546ddfcc9b68be364c)

Co-authored-by: Donghee Na <donghee.na@python.org>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Itamar Oren <itamarost@gmail.com>