loongson/pypi: links for onnx

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

loongson/pypi onnx-1.15.0-cp39-cp39-linux_loongarch64.whl
loongson/pypi onnx-1.15.0-cp38-cp38-linux_loongarch64.whl
loongson/pypi onnx-1.15.0-cp310-cp310-linux_loongarch64.whl
loongson/pypi onnx-1.14.1-cp37-cp37m-linux_loongarch64.whl
loongson/pypi onnx-1.13.1-cp38-cp38-linux_loongarch64.whl
loongson/pypi onnx-1.9.0-cp38-cp38-linux_loongarch64.whl