Add Device Registry Software Update code owners

[Austin Wu (wuqiten)]

Description

Adds package-specific CODEOWNERS coverage for the new Python Device Registry Software Update SDK.

• Reuses the existing %Device Update service and PR label.
• Adds @devlie, @darkoa-msft, and @wuqiten as owners for /sdk/deviceregistry/azure-iot-deviceregistrysoftwareupdate/.
• Corresponding EngSys path work item: 36258.

This PR only changes .github/CODEOWNERS. Because Client Libraries is a protected CODEOWNERS section, this PR may require the approved CODEOWNERS override/automation workflow described at https://aka.ms/azsdk/codeowners.

[azure-pipelines]

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

[github-actions]

[Pilot] PR Pipeline Failure Analysis

What failed

Pipeline: python - codeowners-linter - ci
Task: PowerShell (codeowners-linter)
Result: Failed with exit code 1

The CODEOWNERS linter rejected the new entry on line 227 because the referenced path does not yet exist in the repository.

Relevant pipeline output

##[error]There are linter errors. Please visit https://aka.ms/azsdk/codeownersLinterErrors for guidance on how to handle them.
##[error].github/CODEOWNERS(227,1): error : Error(s) on line 227
Source Line: /sdk/deviceregistry/azure-iot-deviceregistrysoftwareupdate/    `@devlie` `@darkoa-msft` `@wuqiten`
  -/sdk/deviceregistry/azure-iot-deviceregistrysoftwareupdate/ path or file does not exist in repository.
Total run time: 00:00:01.83
Exiting with return code 1

Recommended next steps

• The CODEOWNERS linter requires every listed path to exist in the repository. The path /sdk/deviceregistry/azure-iot-deviceregistrysoftwareupdate/ does not exist yet.
• Either create the SDK package directory (at minimum an empty sdk/deviceregistry/azure-iot-deviceregistrysoftwareupdate/ with a placeholder file such as README.md or setup.py) before merging this CODEOWNERS change, or defer this PR until the package directory is added.
• See https://aka.ms/ci-fix and https://aka.ms/azsdk/codeownersLinterErrors for further guidance.

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 · 20.4 AIC · ⌖ 8.83 AIC · ⊞ 6K · ◷