Test multiarch images against arm64 cluster

We need to be certain that when we ship multiarch images those are working on any arch. For that reason we need to test them against arm64 (we don't have any) clusters as well as amd64 (we run those currently).

This may necessitate corresponding issue in Chart repo

Testing scenarios

• Verify full cloud native setup with arm64:
  • Build a cluster with arm64 node pools
  • Install multi-arch images on the node using test images
  • Run GitLab QA to verify environment
  • Analyse results
• Verify full cloud native setup with x86:
  • Build a cluster with x86 node pools
  • Install multi-arch images on the node using test images
  • Run GitLab QA to verify environment
  • Uninstall Charts and verify it works as expected
  • Upgrade testing with x86
    • Install latest available GitLab Charts image on x86
    • Upgrade to multi-arch image
    • Run GitLab QA to verify environment
• Verify full cloud native setup with mixed cluster (with both amd64 and arm64 pools)
  • Build mixed cluster
  • Install multi-arch images on the node using test images
  • Run GitLab QA to verify environment
• Cloud Native Hybrid testing with arm64
  • Build CNH with arm64
  • Install multi-arch images
  • Run GitLab QA to verify environment
  • Analyse results
• Identify if Operator testing is required
• Discuss with the team strategy for both x86 and arm64 testing in CI