Stewardship for common-ci-tasks and related projects

We have common-ci-tasks and common-template-copier that help us maintain GitLab-projects in a consistent way.

Some of the features currently included:

1. Run renovate
2. Publish packages
3. Run security scans
4. Run tests
5. Setting up projects from terraform using a template
6. ...

We used to share this pretty widely across infrastructure, and slightly beyond (AI-gateway also uses this). I think this could go further into all projects used by Infrastructure Platforms.

For that, I think we might need a better strategy on maintaining these projects, up to now that has been best-effort. But if we share this wider, we should avoid people toiling away writing the same things over and over and instead consider adding it to common-ci-tasks. We'd also need to do better in catching and fixing bugs before all of the engineers receive MRs through renovate.