[ci-scan] Test failure: AsyncEnumerableTests.SerializeAsyncEnumerable_PartialItemFailure_PriorItemsAreFullyWritten on tvOS

## Build Information
Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1438268
Build error leg or test failing: tvos-arm64 Release AllSubsets_Mono - System.Text.Json.Tests

## Error Details

```
[FAIL] System.Text.Json.Serialization.Tests.AsyncEnumerableTests_AsyncPipeSerializer.SerializeAsyncEnumerable_PipeWriter_TopLevelValues_PartialItemFailure_PriorItemsAreFullyWritten
Expected: typeof(System.InvalidOperationException)
Actual: typeof(System.Reflection.TargetInvocationException)
```

Multiple variants affected: AsyncEnumerableTests_AsyncPipeSerializer, AsyncEnumerableTests_AsyncStream (both PipeWriter and non-PipeWriter variants).

## Error Message

`true` only for clear infra flakes. ExcludeConsoleLog skips helix log scanning. -->

```json
{
"ErrorMessage": ["PartialItemFailure_PriorItemsAreFullyWritten", "Actual: typeof(System.Reflection.TargetInvocationException)"],
"ErrorPattern": "",
"BuildRetry": false,
"ExcludeConsoleLog": false
}
```

## Impact on platforms
- runtime-extra-platforms (def 154) / tvos-arm64 Release AllSubsets_Mono / System.Text.Json.Tests / Exit code 1
- Occurrences in window: 3+ (builds 1436493, 1438268, 1440191)

## First build it occurred
- Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1433744
- Finished: 2026-05-25T09:02:27Z
- Persistent across the entire scanned window; true origin may predate 2026-05-24.

---
Filed by [`ci-failure-scan`](https://github.com/dotnet/runtime/blob/main/.github/workflows/ci-failure-scan.md), which scans dnceng-public outer-loop pipelines on `main` and converts stable failures into KBEs and test-disable PRs.

> Generated by [CI Outer-Loop Failure Scanner](https://github.com/dotnet/runtime/actions/runs/26640654776/agentic_workflow) · ● 16.3M · [◷](https://github.com/search?q=repo%3Adotnet%2Fruntime+is%3Aissue+%22gh-aw-workflow-call-id%3A+dotnet%2Fruntime%2Fci-failure-scan%22&type=issues)

### Report
#### Summary
|24-Hour Hit Count|7-Day Hit Count|1-Month Count|
|---|---|---|
|0|0|0|