[CI Failure] Hosting.Browsers (windows-latest) 'Build test project' step fails with generic exit code 1, unrelated to PR changes

## Build Information

Build: https://github.com/microsoft/aspire/actions/runs/33008969799
Build error leg: Tests / Hosting.Browsers / Hosting.Browsers (windows-latest)
Pull request: #19718

## Error Message

```
Process completed with exit code 1. (Build test project step failed; job logs unavailable: 'Failed to fetch logs for job'). No TRX test failures extracted. PR only modifies .github/extensions/aspire-team-app/*.mjs files, unrelated to Hosting.Browsers .NET test project build.
```

## Description

Hosting.Browsers (windows-latest) 'Build test project' step fails with generic exit code 1, unrelated to PR changes

**Type**: flaky-test

## Occurrences

| Date | Build | Job | PR |
|------|-------|-----|----|
| 2026-08-26 | [33008969799](https://github.com/microsoft/aspire/actions/runs/33008969799) | Tests / Hosting.Browsers / Hosting.Browsers (windows-latest) | #19718 |

Start with build 33008969799 and the Tests / Hosting.Browsers / Hosting.Browsers (windows-latest) job, focusing on the failed “Build test project” step. The job logs are unavailable, so determine why it exits with code 1 despite unrelated PR changes. Done means identifying the failure cause and making this Windows CI build pass reliably.

Written by the indexing model from the issue text.