[Build] skip python tests when python version is 3.14 (#26500)

This is a follow up change for
#26397:
(1) Enable python 3.14 for webgpu package
(2) Skip python tests for python 3.14 just like in python cuda package
pipelines.

onnx package does not support python 3.14 right now, so python tests
depending on onnx will fail. Example error in python package pipeline:
```
Traceback (most recent call last):
  File "E:\_work\1\s\build\Release\Release\onnx_backend_test_series.py", line 14, in <module>
    import onnx
ModuleNotFoundError: No module named 'onnx'
```

This is a temporary walkaround to unblock python packaging pipeline for
python 3.14. We can re-enable the test after onnx next release (in a few
weeks?)

Author: tianleiwu

tools/ci_build/github/azure-pipelines/stages/py-cpu-packaging-stage.yml

@@ -177,15 +177,18 @@ stages:
         workingDirectory: '$(Build.ArtifactStagingDirectory)'
         displayName: 'unzip the package'
 
+
       - powershell: |
-         python -m pip uninstall -y onnxruntime onnxruntime-gpu -qq
-         Get-ChildItem -Path $(Build.ArtifactStagingDirectory)/*.whl | foreach {pip --disable-pip-version-check install --upgrade $_.fullname tabulate}
-         Remove-Item -Recurse -Force onnxruntime
-         if ("$(ExtraParam)" -contains "--use_azure") {
-           $env:path="$(Build.SourcesDirectory)\build\${{ parameters.cmake_build_type }}\_deps\vcpkg-src\installed\x64-windows\bin;$(Build.SourcesDirectory)\build\${{ parameters.cmake_build_type }}\_deps\vcpkg-src\installed\x86-windows\bin;$env:path"
-           python onnxruntime_test_python_azure.py
-         }
-         python onnx_backend_test_series.py
+          if ("$(PythonVersion)" -notcontains "3.14") {
+            python -m pip uninstall -y onnxruntime onnxruntime-gpu -qq
+            Get-ChildItem -Path $(Build.ArtifactStagingDirectory)/*.whl | foreach {pip --disable-pip-version-check install --upgrade $_.fullname tabulate}
+            Remove-Item -Recurse -Force onnxruntime
+            if ("$(ExtraParam)" -contains "--use_azure") {
+              $env:path="$(Build.SourcesDirectory)\build\${{ parameters.cmake_build_type }}\_deps\vcpkg-src\installed\x64-windows\bin;$(Build.SourcesDirectory)\build\${{ parameters.cmake_build_type }}\_deps\vcpkg-src\installed\x86-windows\bin;$env:path"
+              python onnxruntime_test_python_azure.py
+            }
+            python onnx_backend_test_series.py
+          }
         workingDirectory: '$(Build.SourcesDirectory)\build\${{ parameters.cmake_build_type }}\${{ parameters.cmake_build_type }}'
         displayName: 'Run Python Tests'
 

tools/ci_build/github/azure-pipelines/stages/py-webgpu-packaging-stage.yml

@@ -23,6 +23,7 @@ parameters:
     - '3.11'
     - '3.12'
     - '3.13'
+    - '3.14'
 
 stages:
     - ${{ each python_version in parameters.PythonVersions }}:

tools/ci_build/github/azure-pipelines/stages/py-win-webgpu-stage.yml

@@ -131,6 +131,8 @@ stages:
 
   - stage: Win_py_webgpu_Wheels_${{ replace(parameters.PYTHON_VERSION,'.','_') }}_Tests
     dependsOn: Win_py_webgpu_Wheels_${{ replace(parameters.PYTHON_VERSION,'.','_') }}_Build
+    # Skip this stage for Python 3.14 for now until onnx package support python 3.14.
+    condition: and(succeeded(), ne('${{ parameters.PYTHON_VERSION }}', '3.14'))
     jobs:
     - job: Win_py_webgpu_Wheels_${{ replace(parameters.PYTHON_VERSION,'.','_') }}_Tests
       workspace: