[CI Failure] Flaky: SealedSecretApplyStepTests wait/timeout test fails intermittently on Linux

## Build Information

Build: https://github.com/microsoft/aspire/actions/runs/32834178883
Build error leg or test failing: Tests / Hosting.Radius / Hosting.Radius (ubuntu-latest) / `Aspire.Hosting.Radius.Tests.Secrets.SealedSecretApplyStepTests.WaitForSealedSecretSynced_StatusMatchesButSecretAbsent_KeepsWaitingThenTimesOut`
Pull request: #19656

## Error Message

```
Assert.True() Failure
Expected: True
Actual: False
at Aspire.Hosting.Radius.Tests.Secrets.SealedSecretApplyStepTests.WaitForSealedSecretSynced_StatusMatchesButSecretAbsent_KeepsWaitingThenTimesOut() in tests/Aspire.Hosting.Radius.Tests/Secrets/SealedSecretApplyStepTests.cs:line 513
```

## Description

Flaky: SealedSecretApplyStepTests wait/timeout test fails intermittently on Linux

**Type**: flaky-test

## Occurrences

| Date | Build | Job | PR |
|------|-------|-----|----|
| 2026-08-25 | [32834178883](https://github.com/microsoft/aspire/actions/runs/32834178883) | Tests / Hosting.Radius / Hosting.Radius (ubuntu-latest) | #19656 |
| 2026-08-27 | [33046510101](https://github.com/microsoft/aspire/actions/runs/33046510101) | Tests / Build native CLI archive (macOS x64) / Build CLI (osx-x64) | #19709 |
| 2026-09-03 | [33696222557](https://github.com/microsoft/aspire/actions/runs/33696222557) | Tests / No-package tests (regular, Aspire.Hosting.Radius.Tests, Hosting.Radius, Hosting.Radius, tests/Asp... / Hosting.Radius (windows-latest) | #18627 |
| 2026-09-04 | [33887016795](https://github.com/microsoft/aspire/actions/runs/33887016795) | Tests / No-package tests (regular, Aspire.Hosting.Radius.Tests, Hosting.Radius, Hosting.Radius, tests/Asp... / Hosting.Radius (windows-latest) | #19478 |

Begin with tests/Aspire.Hosting.Radius.Tests/Secrets/SealedSecretApplyStepTests.cs, especially WaitForSealedSecretSynced_StatusMatchesButSecretAbsent_KeepsWaitingThenTimesOut at line 513, and inspect its timing assumptions. Run the named test repeatedly on the affected test legs and compare the listed failures; done means it reliably enforces the intended timeout behavior without intermittent assertion failures.

Written by the indexing model from the issue text.