[CI Failure] Flaky: AddPythonAppTests.PythonResourceSupportsWithReference fails to create Python virtual environment on Windows runner

## Build Information

Build: https://github.com/microsoft/aspire/actions/runs/32375588350
Build error leg or test failing: Tests / Hosting.Python / Hosting.Python (windows-latest) / `Aspire.Hosting.Python.Tests.AddPythonAppTests.PythonResourceSupportsWithReference`
Pull request: #19335

## Error Message

```
System.InvalidOperationException : Failed to create virtual environment.
at Aspire.Hosting.Python.Tests.AddPythonAppTests.PreparePythonProject(...) in tests\Aspire.Hosting.Python.Tests\AddPythonAppTests.cs:line 327
at Aspire.Hosting.Python.Tests.AddPythonAppTests.CreateTempPythonProject(...) line 275
```

## Description

Flaky: AddPythonAppTests.PythonResourceSupportsWithReference fails to create Python virtual environment on Windows runner

**Type**: flaky-test

## Occurrences

| Date | Build | Job | PR |
|------|-------|-----|----|
| 2026-08-20 | [32375588350](https://github.com/microsoft/aspire/actions/runs/32375588350) | Tests / Hosting.Python / Hosting.Python (windows-latest) | #19335 |

Start in tests\Aspire.Hosting.Python.Tests\AddPythonAppTests.cs at CreateTempPythonProject (line 275) and PreparePythonProject (line 327). Reproduce AddPythonTests.PythonResourceSupportsWithReference on the windows-latest test job and inspect the virtual-environment creation failure. Done means the test reliably creates its Python virtual environment and passes on the Windows runner.

Written by the indexing model from the issue text.