loongson/pypi: links for packaging

INFO: Because this project isn't in the mirror_whitelist, no releases from root/pypi are included.

loongson/pypi packaging-21.3-py3-none-any.whl
loongson/pypi packaging-20.9-py2.py3-none-any.whl
loongson/pypi packaging-20.8-py2.py3-none-any.whl