[CI Failure] Flaky: ProcessGuestLauncherTests.LaunchAsync_WithGracefulServices_BlockingSignalerDoesNotConsumeGracefulBudget times out intermittently on Windows

## Build Information

Build: https://github.com/microsoft/aspire/actions/runs/30055044537
Build error leg or test failing: Tests / Cli / Cli (windows-latest) / `Aspire.Cli.Tests.Projects.ProcessGuestLauncherTests.LaunchAsync_WithGracefulServices_BlockingSignalerDoesNotConsumeGracefulBudget`
Pull request: #18879

## Error Message

```
System.TimeoutException : The operation has timed out.
at Aspire.Cli.Tests.Projects.ProcessGuestLauncherTests.LaunchAsync_WithGracefulServices_BlockingSignalerDoesNotConsumeGracefulBudget() in D:\a\aspire\aspire\tests\Aspire.Cli.Tests\Projects\ProcessGuestLauncherTests.cs:line 186
```

## Description

Flaky: ProcessGuestLauncherTests.LaunchAsync_WithGracefulServices_BlockingSignalerDoesNotConsumeGracefulBudget times out intermittently on Windows

**Type**: flaky-test

## Occurrences

| Date | Build | Job | PR |
|------|-------|-----|----|
| 2026-07-24 | [30055044537](https://github.com/microsoft/aspire/actions/runs/30055044537) | Tests / Cli / Cli (windows-latest) | #18879 |
| 2026-08-11 | [31538996343](https://github.com/microsoft/aspire/actions/runs/31538996343) | Tests / Cli / Cli (windows-latest) | #19221 |
| 2026-08-13 | [31668464647](https://github.com/microsoft/aspire/actions/runs/31668464647) | Tests / Cli / Cli (windows-latest) | #19331 |
| 2026-08-13 | [31739682865](https://github.com/microsoft/aspire/actions/runs/31739682865) | Tests / Cli / Cli (windows-latest) | #16842 |

Start with tests/Aspire.Cli.Tests/Projects/ProcessGuestLauncherTests.cs, especially LaunchAsync_WithGracefulServices_BlockingSignalerDoesNotConsumeGracefulBudget at line 186. Reproduce the test on the windows-latest CI leg and inspect the timeout behavior; done means the test no longer times out intermittently across the reported Windows runs.

Written by the indexing model from the issue text.