[8.19] (backport #10172) Deduplicate extensions when generating otel config

[mergify]

What does this PR do?

Ensures the extension list in the otel config we generate for components always has only one instance of each extension. Currently, we get the same beatsauth extension multiple times, which only works due to a quirk of otel's config processing.

Why is it important?

The config we currently generate for the otel collector is invalid, and is only accepted and works correctly due to implementation details.

Checklist

• I have read and understood the pull request guidelines of this project.
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• [ ] I have added an entry in ./changelog/fragments using the changelog tool
• [ ] I have added an integration test or an E2E test

Related issues

• Closes [beats receivers] Beatsauth extension is not removed or reused when configuration is reloaded #10154

---

This is an automatic backport of pull request #10172 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 5aacbcb has failed:

On branch mergify/bp/8.19/pr-10172
Your branch is up to date with 'origin/8.19'.

You are currently cherry-picking commit 5aacbcbaa.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   internal/pkg/otel/translate/otelconfig.go
	both modified:   internal/pkg/otel/translate/otelconfig_test.go

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[mergify]

This pull request has not been merged yet. Could you please review and merge it @swiatekm? 🙏

[elastic-sonarqube]

Quality Gate passed

Issues
1 New issue
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
92.9% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube

[elasticmachine]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 8e99109

Failed CI Steps

• Win2022:sudo:fleet
• Win2022:sudo:fleet
• Win2025:sudo:standalone-upgrade

History

• 💔 Build #27668 failed 1b7a5e8

cc @swiatekm