ci: release lightpanda-python on version tags

Add an update-python-package job that creates the matching release on
lightpanda-io/lightpanda-python (same distribution-app pattern as the
docker and homebrew jobs). That release triggers the wheels workflow
there, replacing its daily track-browser polling; its publish to PyPI
still waits for approval on that repo's pypi environment.

The distribution app needs contents write access to lightpanda-python.