to create a training cpu package for torch-ort documentation

[liqunfu]

Description: to create a training cpu package for torch-ort documentation

Motivation and Context

• torch-ort needs an onnxruntime-training wheel to be imported in order to generate training document. The document generating system does not have gpu device. To make it work, it needs a wheel that can be imported. The wheel generated with this new pipeline fit the need.

[snnn]

the document generating system does not have gpu device.

Wait. I think Ryan is fixing this. onnxruntime gpu package shouldn't need a GPU. Then you don't need to do this? #7939

[thiagocrepaldi]

LGTM