Mono iOS test failures with "The "AppleAppBuilderTask" task failed unexpectedly." in ProxyProjectForAOTOnHelix

## Build Information
Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1396034
Build error leg or test failing: System.Runtime.Tests.WorkItemExecution
Pull request: https://github.com/dotnet/runtime/pull/127336

## Error Message

Fill the error message using [step by step known issues guidance](https://github.com/dotnet/arcade/blob/main/Documentation/Projects/Build%20Analysis/KnownIssueJsonStepByStep.md).

```json
{
"ErrorMessage": "The \"AppleAppBuilderTask\" task failed unexpectedly.",
"ErrorPattern": "",
"BuildRetry": false,
"ExcludeConsoleLog": false
}
```

### Known issue validation
**Build: :mag_right:** https://dev.azure.com/dnceng-public/public/_build/results?buildId=1396034
**Error message validated:** `[The "AppleAppBuilderTask" task failed unexpectedly.`]
**Result validation:** :white_check_mark: Known issue matched with the provided build.
**Validation performed at:** 4/25/2026 12:23:46 PM UTC

### Report

|Build|Repository|Test|Pull Request|
|---|---|---|---|
|[1594486](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594486)|dotnet/runtime|[System.Runtime.CompilerServices.VisualC.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594486&view=ms.vss-test-web.build-test-results-tab&runId=44015844&resultId=100639)||
|[1592042](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1592042)|dotnet/runtime|[System.Net.ServerSentEvents.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1592042&view=ms.vss-test-web.build-test-results-tab&runId=43950302&resultId=117809)||
|[1591449](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1591449)|dotnet/runtime|[Invariant.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1591449&view=ms.vss-test-web.build-test-results-tab&runId=43934756&resultId=100152)|dotnet/runtime#133575|
|[1590455](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1590455)|dotnet/runtime|[iOS.CoreCLR.R2R.Test.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1590455&view=ms.vss-test-web.build-test-results-tab&runId=43902892&resultId=100002)|dotnet/runtime#133575|
|[1585548](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1585548)|dotnet/runtime|[System.Runtime.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1585548&view=ms.vss-test-web.build-test-results-tab&runId=43751696&resultId=100001)||
|[1584026](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1584026)|dotnet/runtime|[System.Collections.Immutable.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1584026&view=ms.vss-test-web.build-test-results-tab&runId=43705194&resultId=100043)||
|[1583617](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583617)|dotnet/runtime|[System.Runtime.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583617&view=ms.vss-test-web.build-test-results-tab&runId=43695202&resultId=100168)||
|[1583227](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583227)|dotnet/runtime|[System.Xml.Schema.Extensions.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583227&view=ms.vss-test-web.build-test-results-tab&runId=43684874&resultId=100205)||
|[1582095](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1582095)|dotnet/runtime|[System.ServiceModel.Syndication.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1582095&view=ms.vss-test-web.build-test-results-tab&runId=43651118&resultId=100176)||
|[1573540](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1573540)|dotnet/runtime|[System.Text.Encoding.CodePages.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1573540&view=ms.vss-test-web.build-test-results-tab&runId=43351756&resultId=161892)||
|[1561753](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1561753)|dotnet/runtime|[System.Linq.AsyncEnumerable.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1561753&view=ms.vss-test-web.build-test-results-tab&runId=43001566&resultId=159160)||
|[1561442](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1561442)|dotnet/runtime|[System.Xml.Linq.SDMSample.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1561442&view=ms.vss-test-web.build-test-results-tab&runId=42990624&resultId=159747)|dotnet/runtime#132348|
|[1559993](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1559993)|dotnet/runtime|[Microsoft.Extensions.Logging.Testing.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1559993&view=ms.vss-test-web.build-test-results-tab&runId=42946296&resultId=161740)||
|[1554672](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1554672)|dotnet/runtime|[System.IO.Pipes.Tests.WorkItemExecution](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1554672&view=ms.vss-test-web.build-test-results-tab&runId=42791116&resultId=161099)||
#### Summary
|24-Hour Hit Count|7-Day Hit Count|1-Month Count|
|---|---|---|
|0|4|14|