loongson/pypi: links for chemprop-contrib

loongson/mirror chemprop_contrib-2025.11.30.tar.gz
loongson/mirror chemprop_contrib-2025.11.30-py3-none-any.whl
loongson/mirror chemprop_contrib-2025.11.1.tar.gz
loongson/mirror chemprop_contrib-2025.11.1-py3-none-any.whl