[3.9] bpo-43757: Make pathlib use os.path.realpath() to resolve symlinks in a path (GH-25264) by ambv · Pull Request #135035 · python/cpython

Also adds a new "strict" argument to realpath() to avoid changing the default behaviour of pathlib while sharing the implementation.

(cherry-picked from commit baecfbd)

This is necessary for gh-135034.