Revert Windows GPU python 3.8 and python 3.9 changes in the release branch

[snnn]

Description:

Revert python 3.8 changes

1. Revert "Revert some pipeline changes in Add python 3.9 support #5874"
2. Revert "Add python 3.9 support (Add python 3.9 support #5874)"
3. Revert "Add support for Python 3.8+ on Windows when CUDA is enabled (Add support for Python 3.8+ on Windows when CUDA is enabled #5956)"
4. Cherry-pick bug fix in build.py which prevents running some unit tests #5990 to validate the changes.
5. Regenerate all the CI build docker images to ensure things are consistent.
   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.

Will need to reopen #5697 #4035 #2664 #5963

[duli2012]

python 3.8 is still here?

[duli2012]

same as above

[snnn]

It was added long ago. In the past a few releases, we have almost full support for python 3.8 except lacking Windows GPU package and ARM package.

[jywu-msft]

what do you think of just respecting CUDA_PATH as I suggested in #5962 (comment)
rather than hardcoding CUDA 10.2?

[snnn]

what do you think of just respecting CUDA_PATH as I suggested in #5962 (comment)
rather than hardcoding CUDA 10.2?

Sorry I have no idea. I think the safest way would be revert the recent changes first, get the release branch back to a good state, then we can think how to do it better.

[jywu-msft]

what do you think of just respecting CUDA_PATH as I suggested in #5962 (comment)
rather than hardcoding CUDA 10.2?

Sorry I have no idea. I think the safest way would be revert the recent changes first, get the release branch back to a good state, then we can think how to do it better.

I have a fix soon (hopefully). Let me share a branch with you. Let me know what you think.