[CI Failure] Azure.Search.Documents (ubuntu-latest) test run crashes with exit code 134 (SIGABRT), triggering hang dump check

## Build Information

Build: https://github.com/microsoft/aspire/actions/runs/34941224700
Build error leg: Tests / No-package tests (regular, Aspire.Azure.Search.Documents.Tests, Azure.Search.Documents, Azure.Sea... / Azure.Search.Documents (ubuntu-latest)
Pull request: #20011

## Classification Analysis

Exit code 134 (SIGABRT) surfaced during post-processing steps ('Check for hang dump files', 'Generate test results summary'), indicating a test host crash unrelated to PR changes. Job logs unavailable. PR only touches Aspire.Hosting.Azure, unrelated to Azure.Search.Documents tests.

## Failure Information

Job output snippet

### Job: Tests / No-package tests (regular, Aspire.Azure.Search.Documents.Tests, Azure.Search.Documents, Azure.Sea... / Azure.Search.Documents (ubuntu-latest)

- Conclusion: failure

- Failed Steps: Check for hang dump files, Generate test results summary

- Annotations: Process completed with exit code 134. (x2)

- Logs: (Failed to fetch logs for job 104290723437)

PR changed files (unrelated to Azure.Search.Documents): src/Aspire.Hosting.Azure/AzureEnvironmentResourceExtensions.cs, tests/Aspire.Hosting.Azure.Tests/AzureEnvironmentResourceExtensionsTests.cs

## Description

Azure.Search.Documents (ubuntu-latest) test run crashes with exit code 134 (SIGABRT), triggering hang dump check

**Type**: infra-failure

## Occurrences

| Date | Build | Job | PR |
|------|-------|-----|----|
| 2026-09-15 | [34941224700](https://github.com/microsoft/aspire/actions/runs/34941224700) | Tests / No-package tests (regular, Aspire.Azure.Search.Documents.Tests, Azure.Search.Documents, Azure.Sea... / Azure.Search.Documents (ubuntu-latest) | #20011 |

Start with build 34941224700 and job 104290723437, focusing on the Azure.Search.Documents ubuntu-latest test run and the failed “Check for hang dump files” and “Generate test results summary” steps. Logs were unavailable, so determine whether the exit-code 134 crash can be reproduced or explained by CI infrastructure; done means identifying a supported cause and a verified corrective change or documenting the failure as transient.

Written by the indexing model from the issue text.