[3.12] gh-105578: Add more usage examples to `typing.AnyStr` docs (GH-107045) (#107503)

gh-105578: Add more usage examples to `typing.AnyStr` docs (GH-107045)

``typing.AnyStr`` has different semantics to ``str | bytes``, which often leads to user confusion
(cherry picked from commit f877b32b879f2076bb1c52826af0c28ebf1aaeed)

Co-authored-by: Michael The <michael-the1@users.noreply.github.com>