Pin Onnx Version (#20073)
### Description
1. change in build.py is to fix DML exception
(https://dev.azure.com/onnxruntime/onnxruntime/_build?definitionId=10&_a=summary)
2. change in requirements.txt is to fix exception in python packaging
pipeline.
https://dev.azure.com/aiinfra/Lotus/_build/results?buildId=430433&view=results
### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
---------
Co-authored-by: Yi Zhang <your@email.com>
