loongson/pypi: links for libsg

loongson/mirror libsg-0.0.1rc7.tar.gz
loongson/mirror libsg-0.0.1rc7-py3-none-any.whl
loongson/mirror libsg-0.0.1rc6.tar.gz
loongson/mirror libsg-0.0.1rc6-py3-none-any.whl
loongson/mirror libsg-0.0.1rc5.tar.gz
loongson/mirror libsg-0.0.1rc5-py3-none-any.whl