[8.x](backport #6938) chore: update elastic-agent-libs to v0.18.8

[mergify]

What does this PR do?

This PR updates elastic-agent-libs to the most recent version.

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

Disruptive User Impact

How to test this PR locally

Related issues

• For https://github.com/elastic/security/issues/6104

---

This is an automatic backport of pull request #6938 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of f34071c has failed:

On branch mergify/bp/8.x/pr-6938
Your branch is up to date with 'origin/8.x'.

You are currently cherry-picking commit f34071c29.
  (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:
	modified:   NOTICE.txt
	new file:   changelog/fragments/1740772872-mitigate-symlink-following-when-rotating-files.yaml

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   go.mod
	both modified:   go.sum

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]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 5c721c0

History

• 💔 Build #18210 failed 6a2faeb
• 💔 Build #18200 failed 8a55884

cc @mauri870