loongson/pypi: links for billiard

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

loongson/pypi billiard-3.6.4.0-py3-none-any.whl
loongson/pypi billiard-3.6.3.0-py3-none-any.whl
loongson/pypi billiard-3.5.0.2-py3-none-any.whl
loongson/pypi billiard-3.3.0.23-py3-none-any.whl