Python docs release failures

Example failure: https://dev.azure.com/azure-sdk/internal/_build/results?buildId=6091086&view=logs&j=cebc98c9-efae-55e8-a8e2-6bab68548f30

@scbedd did some initial investigation as this intersects with various Python-related EngSys work that's also ongoing.

Errors show:

```
subprocess.CalledProcessError: Command '['pip', 'download', '--dest', 'dist_temp/0', '--no-deps', 'azure-mgmt-containerservice==41.1.0b1', '--extra-index-url', 'https://pkgs.dev.azure.com/azure-sdk/public/_packaging/azure-sdk-for-python/pypi/simple/', '--no-binary=:all:']' returned non-zero exit status 1.
```

Py2docfx is attempting to download the package but the download fails.

This could block docs release for Python packages so I'm looking into fixes here.