onnxruntime

update pipline python version from 3.8 to 3.12 (#22517)

### Description
As the python3.8 is going to reach EOL. 

https://discuss.python.org/t/python-3-13-0-final-has-been-released/
https://discuss.python.org/t/python-3-8-is-now-officially-eol/66983

we update our ci pipeline python version which still using 3.8 to 3.12