[Cosmos] Prepare azure-cosmos 4.17.1 release

[Tomas Varon (tvaron3)]

Summary

Manual release preparation for azure-cosmos version 4.17.1, dated 2026-09-16.

• Replace the 4.17.1 Unreleased date with 2026-09-16 and remove empty Features Added, Breaking Changes, and Other Changes headings.
• Preserve both bug fixes from [Cosmos] Keep existing-child routing updates incremental #49026: avoid unnecessary full routing-map refreshes for removed ancestors, and prevent older partition metadata revisions from overwriting newer revisions during cascading splits.
• Keep _version.py unchanged at 4.17.1. This PR changes only sdk/cosmos/azure-cosmos/CHANGELOG.md and reuses the existing approved and reviewed commit unchanged.

[azure-pipelines]

Azure Pipelines:
Successfully started running 3 pipeline(s).
7 pipeline(s) were filtered out due to trigger conditions.
There may be pipelines that require an authorized user to comment /azp run to run.

[azure-pipelines]

Azure Pipelines:
Successfully started running 2 pipeline(s).
7 pipeline(s) were filtered out due to trigger conditions.
There may be pipelines that require an authorized user to comment /azp run to run.

[Copilot]

🟢 Approval recommended

No unresolved blocking issues were identified.

Pull request overview

Prepares the azure-cosmos 4.17.1 release notes dated 2026-09-16.

Changes:

• Dates the 4.17.1 changelog entry.
• Removes empty sections.
• Preserves both fixes from PR #49026.

File summaries

File	Description
sdk/cosmos/azure-cosmos/CHANGELOG.md	Finalizes the 4.17.1 release notes.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Lite (auto)

Note

Copilot is running an experiment and ran this review at Lite.

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[github-actions]

[Pilot] PR Pipeline Failure Analysis

What failed

The python - cosmos - native-test check (and its associated Build Analyze check) failed on Azure Pipelines build 6844315:

• python - cosmos - native-test — FAILURE — https://dev.azure.com/azure-sdk/fadad8ea-1e34-4d7a-9016-fd29b14e8b94/_build/results?buildId=6844315
• python - cosmos - native-test (Build Analyze) — FAILURE — https://dev.azure.com/azure-sdk/fadad8ea-1e34-4d7a-9016-fd29b14e8b94/_build/results?buildId=6844315&view=logs&jobId=b70e5e73-bbb6-5567-0939-8415943fadb9

The automated azsdk ci analyze run returned no azure_pipeline_analyses or github_workflow_analyses entries, and the accompanying failed-test-results artifact was empty. This indicates the workflow could not pull detailed logs or test results from this internal Azure DevOps pipeline (it is only visible in the failing_pull_request_checks summary from the GitHub check run), so no specific failing test, stack trace, or file/line evidence is available to diagnose the root cause from this environment.

Relevant pipeline output

{
  "azure_pipeline_analyses": [],
  "github_workflow_analyses": [],
  "failing_pull_request_checks": [
    {
      "name": "python - cosmos - native-test",
      "conclusion": "FAILURE",
      "details_url": "https://dev.azure.com/azure-sdk/fadad8ea-1e34-4d7a-9016-fd29b14e8b94/_build/results?buildId=6844315"
    },
    {
      "name": "python - cosmos - native-test (Build Analyze)",
      "conclusion": "FAILURE",
      "details_url": "https://dev.azure.com/azure-sdk/fadad8ea-1e34-4d7a-9016-fd29b14e8b94/_build/results?buildId=6844315&view=logs&jobId=b70e5e73-bbb6-5567-0939-8415943fadb9"
    }
  ],
  "operation_status": "Succeeded"
}

Recommended next steps

• This workflow does not have the user's Azure DevOps identity and cannot fetch the internal build's logs or test-result artifacts directly, so a root-cause diagnosis could not be produced here.

• Analyze the pipeline locally while authenticated to Azure DevOps:

  azsdk ci analyze https://github.com/Azure/azure-sdk-for-python/pull/49045 --output json

• Alternatively, open the build directly in the Azure DevOps UI to inspect logs and failed test details: https://dev.azure.com/azure-sdk/fadad8ea-1e34-4d7a-9016-fd29b14e8b94/_build/results?buildId=6844315

• See https://aka.ms/ci-fix

Copilot detected the failing pipeline and generated the analysis above. To have it attempt a
fix automatically, reply with @copilot please fix the failing pipeline on this PR.

Generated by Pipeline Analysis Next Steps · auto · 57.4 AIC · ⌖ 1.89 AIC · ⊞ 9.2K · ◷