[CI Failure] Flaky: DashboardClientTests.SubscribeResources_ReplicaStateOwnedPropertyMetadataChanged_EmitsParentChange fails with Assert.True() Failure

## Build Information

Build: https://github.com/microsoft/aspire/actions/runs/32327702249
Build error leg or test failing: Tests / Dashboard / Dashboard (ubuntu-latest) / `Aspire.Dashboard.Tests.Model.DashboardClientTests.SubscribeResources_ReplicaStateOwnedPropertyMetadataChanged_EmitsParentChange`
Pull request: #19527

## Error Message

```
Assert.True() Failure
Expected: True
Actual: False
at Aspire.Dashboard.Tests.Model.DashboardClientTests.SubscribeResources_ReplicaStateOwnedPropertyMetadataChanged_EmitsParentChange() in /_/tests/Aspire.Dashboard.Tests/Model/DashboardClientTests.cs:line 740
```

## Description

Flaky: DashboardClientTests.SubscribeResources_ReplicaStateOwnedPropertyMetadataChanged_EmitsParentChange fails with Assert.True() Failure

**Type**: flaky-test

## Occurrences

| Date | Build | Job | PR |
|------|-------|-----|----|
| 2026-08-20 | [32327702249](https://github.com/microsoft/aspire/actions/runs/32327702249) | Tests / Dashboard / Dashboard (ubuntu-latest) | #19527 |

Start with tests/Aspire.Dashboard.Tests/Model/DashboardClientTests.cs at line 740 and the SubscribeResources_ReplicaStateOwnedPropertyMetadataChanged_EmitsParentChange test. Review the failing GitHub Actions run and reproduce the test to identify why Assert.True() sometimes receives false. Done means the test reliably passes in the Dashboard CI job without masking the behavior it verifies.

Written by the indexing model from the issue text.