[3.13] Add missing fullstop `.` to whatsnew/3.8.rst (GH-126553) (#126672)

Add missing fullstop `.` to whatsnew/3.8.rst (GH-126553)
(cherry picked from commit 82269c7d580e1aad71ff11fe891cf7f97eb45703)

Co-authored-by: Rafael Fontenelle <rffontenelle@users.noreply.github.com>
1 file changed