[3.12] GH-109190: Announce final release in What's New in Python 3.12 (GH-110117) (#110215)

GH-109190: Announce final release in What's New in Python 3.12 (GH-110117)

Prepare What's New in Python 3.12 for final release
(cherry picked from commit 6139bf5e0c755ed22bdfb027a5299493f0c71be9)

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>