[3.10] bpo-44246: Update What's New for importlib.metadata. (GH-26408) (GH-26415)

* [bpo-44246](): Update What's New for importlib.metadata.

Bump version of importlib_metadata included.
Add note about compatibility notice and fix link to entry_points documentation.
Add note about removal of access by index on Distribution.entry_points.

* Fix syntax mistake in issue reference.

Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>

* Fix broken reference in entry-points.

Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
(cherry picked from commit 28f12c9f4f39d283d823d81e311d863526dfdb54)


Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>

Automerge-Triggered-By: GH:jaraco