Consolidate Renovate usage

Currently there are two different approaches of leveraging Renovate for dependency updates:

• https://gitlab.com/gitlab-com/gl-infra/common-ci-tasks

  • Per project CI job, required CI include + renovate.json config
  • Custom container image, only specific tooling is installed
  • Focuses on:
    • Security/isolation by running one job per project
    • Custom tooling backed into the image to generate/update templates/non-standard files

• https://gitlab.com/gitlab-com/gl-infra/renovate/renovate-ci

  • Global CI job with renovate-runner(auto-discovery), required renovate.json config
  • Upstream images used, DinD approach, language specific images are used based on project code/files
  • Focuses on:
    • Low maintenance, easy onboarding, upstream maintained
    • Efficiency by running a global CI job that caches dependencies data for all projects

We should consolidate and shift to use a single method to avoid confusion, collision and repetition.