Update GitLab Helm chart to support Cgroups

Make necessary adjustments to Helm chart to support running Gitaly in Kubernetes with cgroups v2 support.

Implement the approach documented at #5833 (comment 1852767923)

• Develop a Golang binary to locate cgroup, update ownership, inject cgroup path into secrets
• Create new container image in CNG (cgroups init container) with the above binary
• Update GitLab Helm chart to conditionally (opt-in) enable cgroups v2 support