loongson/pypi: links for pycairo

loongson/pypi pycairo-1.18.2-cp37-cp37m-linux_loongarch64.whl
loongson/pypi pycairo-1.18.2-cp27-cp27mu-linux_loongarch64.whl
loongson/pypi pycairo-1.16.2-cp37-cp37m-linux_loongarch64.whl