[3.12] gh-97850: Note in py312 whatsnew that `importlib.util.set_loader` and `importlib.util.module_for_loader` have been removed (GH-108719) (#108723)

gh-97850: Note in py312 whatsnew that `importlib.util.set_loader` and `importlib.util.module_for_loader` have been removed (GH-108719)

Note in py312 whatsnew that `importlib.util.set_loader` and `importlib.util.module_for_loader` have been removed
(cherry picked from commit 013a99a47b3299f48cf7f95aa451a116441b029c)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>