disables qnn in ort training cpu pipeline (#21510)
### Description
<!-- Describe your changes. -->
`enable_windows_arm64_qnn` and `enable_windows_x64_qnn` are true by
default but unnecessary for training. This change explicitly sets these
parameters to false for training pipeline.
### 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. -->
ORT 1.19 Release Preparation
