loongson/pypi: links for pyqt5-sip

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

loongson/pypi PyQt5_sip-12.11.0.tar.gz
loongson/pypi PyQt5_sip-12.11.0-cp39-cp39-linux_loongarch64.whl