Fatal error during the build with System.Net.Http.HttpConnectionPool.ConnectAsync on the callstack

```
Building managed test group 1: "D:\a\_work\1\s\\dotnet.cmd" msbuild D:\a\_work\1\s\src\tests\build.proj /t:CopyAllNativeTestProjectBinaries "/p:TargetArchitecture=x64" "/p:Configuration=Checked" "/p:LibrariesConfiguration=Debug" "/p:TasksConfiguration=Checked" "/p:TargetOS=windows" "/p:ToolsOS=" "/p:PackageOS=" "/p:RuntimeFlavor=coreclr" "/p:RuntimeVariant=" "/p:CLRTestBuildAllTargets=" "/p:UseCodeFlowEnforcement=" "/p:__TestGroupToBuild=1" "/p:__SkipRestorePackages=1" /nodeReuse:false /maxcpucount "/p:UseMonoRuntime=false" /bl:D:\a\_work\1\s\artifacts\/log/Checked/InnerManagedTestBuild.1.binlog "/p:DevTeamProvisioning=-"
D:\a\_work\1\s\.dotnet
Fatal error.
Internal CLR error. (0x80131506)
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[System.Net.Http.HttpConnectionPool+d__54, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]](d__54 ByRef)
at System.Runtime.CompilerServices.AsyncValueTaskMethodBuilder`1[[System.__Canon, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Start[[System.Net.Http.HttpConnectionPool+d__54, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]](d__54 ByRef)
at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(System.String, Int32, System.Net.Http.HttpRequestMessage, Boolean, System.Threading.CancellationToken)
at System.Net.Http.HttpConnectionPool+d__53.MoveNext()
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[System.Net.Http.HttpConnectionPool+d__53, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]](d__53 ByRef)
at System.Runtime.CompilerServices.AsyncValueTaskMethodBuilder`1[[System.ValueTuple`4[[System.__Canon, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.__Canon, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Start[[System.Net.Http.HttpConnectionPool+d__53, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]](d__53 ByRef)
at System.Net.Http.HttpConnectionPool.ConnectAsync(System.Net.Http.HttpRequestMessage, Boolean, System.Threading.CancellationToken)
at System.Net.Http.HttpConnectionPool+d__81.MoveNext()
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[System.Net.Http.HttpConnectionPool+d__81, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]](d__81 ByRef)
at System.Runtime.CompilerServices.AsyncValueTaskMethodBuilder`1[[System.__Canon, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Start[[System.Net.Http.HttpConnectionPool+d__81, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]](d__81 ByRef)
at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(System.Net.Http.HttpRequestMessage, Boolean, System.Threading.CancellationToken)
at System.Net.Http.HttpConnectionPool+d__80.MoveNext()
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1+AsyncStateMachineBox`1[[System.Threading.Tasks.VoidTaskResult, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Net.Http.HttpConnectionPool+d__80, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]].ExecutionContextCallback(System.Object)
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(System.Threading.Thread, System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1+AsyncStateMachineBox`1[[System.Threading.Tasks.VoidTaskResult, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Net.Http.HttpConnectionPool+d__80, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]].MoveNext(System.Threading.Thread)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1+AsyncStateMachineBox`1[[System.Threading.Tasks.VoidTaskResult, System.Private.CoreLib, Version=11.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Net.Http.HttpConnectionPool+d__80, System.Net.Http, Version=11.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a]].ExecuteFromThreadPool(System.Threading.Thread)
at System.Threading.ThreadPoolWorkQueue.Dispatch()
```

## Build Information
Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1326390&view=logs&j=36023878-3ad4-5624-c1ed-575c64898e0b
Build error leg or test failing: Build / coreclr Pri0 Runtime Tests Run windows x64 checked / Copy native test components to test output folder
Pull request: https://github.com/dotnet/runtime/pull/125307

## 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": ["Fatal error","System.Net.Http.HttpConnectionPool.ConnectAsync"],
"ErrorPattern": "",
"BuildRetry": false,
"ExcludeConsoleLog": false
}
```

### Known issue validation
**Build: :mag_right:** https://dev.azure.com/dnceng-public/public/_build/results?buildId=1326390
**Error message validated:** `[Fatal error`]
**Result validation:** :white_check_mark: Known issue matched with the provided build.
**Validation performed at:** 3/9/2026 5:12:28 PM UTC

### Known issue validation
**Build: :mag_right:** https://dev.azure.com/dnceng-public/public/_build/results?buildId=1326390
**Error message validated:** `[Fatal error System.Net.Http.HttpConnectionPool.ConnectAsync`]
**Result validation:** :white_check_mark: Known issue matched with the provided build.
**Validation performed at:** 3/9/2026 5:13:18 PM UTC

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