[8.17] (backport #8340) ci: update all n1-standard-4 type runners to n2-standard-4

[mergify]

What does this PR do?

This PR updates the machine type for a Buildkite pipeline step in .buildkite/bk.integration.pipeline.yml, changing it from n1-standard-4 to n2-standard-4.

Why is it important?

The n1 machine series on GCP is older, with inferior performance and cost efficiency compared to the newer n2 series. Moving to n2-standard-4 aligns with the improvements adopted in previous CI upgrades (e.g., n2-standard-8), offering better resource availability and stability in CI jobs.

This change also ensures consistency across Buildkite steps and prepares us for any potential future deprecation of n1 machine types by GCP.

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

None. This is a CI-only change and has no impact on the Elastic Agent runtime behavior, packaging, or user-facing interfaces.

How to test this PR locally

This change affects CI configuration only. The pipeline will be automatically exercised when the Buildkite job runs.

Related issues

• Follows up on review feedback promoting use of n2 series for improved performance and consistency

  ---

  This is an automatic backport of pull request ci: update all n1-standard-4 type runners to n2-standard-4 #8340 done by Mergify.

[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: c891d4d

History

• 💔 Build #21849 failed c891d4d

cc @pkoutsovasilis