loongson/pypi: links for pyqt5

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

loongson/pypi PyQt5-5.15.10-cp37-abi3-linux_loongarch64.whl
loongson/pypi PyQt5-5.15.7.tar.gz
loongson/pypi PyQt5-5.15.7-cp39-abi3-linux_loongarch64.whl
loongson/pypi PyQt5-5.15.4-cp37-abi3-linux_loongarch64.whl