loongson/pypi: links for buildstack

loongson/mirror buildstack-6.3.0.tar.gz
loongson/mirror buildstack-6.2.1.tar.gz
loongson/mirror buildstack-6.2.0.tar.gz
loongson/mirror buildstack-6.1.1.tar.gz
loongson/mirror buildstack-6.1.0.tar.gz
loongson/mirror buildstack-6.0.5.tar.gz
loongson/mirror buildstack-6.0.4.tar.gz
loongson/mirror buildstack-6.0.3.tar.gz
loongson/mirror buildstack-6.0.1.tar.gz
loongson/mirror buildstack-5.8.0.tar.gz
loongson/mirror buildstack-5.7.1.tar.gz