root/pypi: links for xpersist

root/pypi xpersist-2021.12.17.tar.gz
root/pypi xpersist-2021.12.17-py3-none-any.whl
root/pypi xpersist-2021.12.16.tar.gz
root/pypi xpersist-2021.12.16-py3-none-any.whl