Create/Run repository maintenance jobs with read-only root filesystem

[revog]

Describe the problem/challenge you have
Due to security/policy reasons we'd like to run the maintenance jobs with read-only root filesystem

Describe the solution you'd like
Looking for an option in the helm deployment to set the following in the maintenance pod/job:

...
containerSecurityContext:
  readOnlyRootFilesystem: true
...

Anything else you would like to add:
For other components (velero server, node-agents, crd job) it is possible to set the option above within the values.yaml.

Environment:

• helm version (use helm version): 3.12.0
• helm chart version and app version (use helm list -n <YOUR NAMESPACE>): 8.1.0
• Kubernetes version (use kubectl version): v1.31.1
• Kubernetes installer & version: RKE2
• Cloud provider or hardware configuration:
• OS (e.g. from /etc/os-release): SLES15