[3.13] Add link in the `importlib.metadata.version()` docs (GH-130739) (#130761)

Add link in the `importlib.metadata.version()` docs (GH-130739)

Link the specification for the returned data makes it clearer what this is
and what the format of the version string can be.
(cherry picked from commit c71e55869e7bc56b2bd04f3055f810026a66c076)

Co-authored-by: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>