[8.19] (backport #11718) [OTEL] Hide healthcheckv2 from agent status.

[mergify]

What does this PR do?

Hides the healthcheckv2 extension from the elastic-agent status output.

Why is it important?

This extension is injected by the elastic-agent so it should not be included in the status as its not created by the user.

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 (covered by unit test)

Disruptive User Impact

The healthcheckv2 will no longer be included in status output.

How to test this PR locally

Run the elastic-agent with OTEL enabled, run elastic-agent status and observe that the healthcheckv2 extension is no longer in the status output.

Related issues

• Closes [OTEL] healthcheckv2extension should be hidden in elastic-agent status output #11714

---

This is an automatic backport of pull request #11718 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 81d77f5 has failed:

On branch mergify/bp/8.19/pr-11718
Your branch is up to date with 'origin/8.19'.

You are currently cherry-picking commit 81d77f53e.
  (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)

Changes to be committed:
	new file:   changelog/fragments/1765377327-hide-healthcheckv2-from-status-output.yaml
	modified:   internal/pkg/otel/manager/execution_subprocess.go
	modified:   internal/pkg/otel/manager/manager_test.go

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

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)

[elasticmachine]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 8bb6c19

Failed CI Steps

• 📦 amd64: FIPS tar.gz
• x86_64:sudo: fleet - platform-ingest-elastic-agent-debian-11-1762801856

cc @blakerouse