loongson/pypi: links for tensorflow

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

loongson/pypi tensorflow-2.6.0-cp38-cp38-linux_loongarch64.whl
loongson/pypi tensorflow-2.6.0-cp37-cp37m-linux_loongarch64.whl
loongson/pypi tensorflow-2.4.0-cp37-cp37m-linux_loongarch64.whl