Add UsePython Task in Nuget Publish workflow (#21144)
### Description
Otherwise it would fail in
https://github.com/microsoft/onnxruntime/blob/b95982e588e2d433958aa9aa82557b714ec4e3de/tools/ci_build/github/azure-pipelines/publish-nuget.yml#L78-L81
### Motivation and Context
The Windows CPU image is migrated to managed image
### Verification Link
https://dev.azure.com/aiinfra/Lotus/_build?definitionId=1313
