gh-113174: Sync with importlib_metadata 7.0 (#113175)

* Sync with importlib_metadata 7.0.0

* Add blurb

* Update docs to reflect changes.

* Link datamodel docs for object.__getitem__

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

* Add what's new for removed __getattr__

* Link datamodel docs for object.__getitem__

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

* Add exclamation point, as that seems to be used for other classes.

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