Abstract CI/CD pipelines

Enable SDLC processes to be infrastructure provider independent, and capable of being concurrently deployed and federated.

Redevelop the deployment and management  processes for the CI/Pipeline machinery, so that it can be rebuilt and reconfigured on demand to make the entire Common Platform and Services managed by the Systems Team  portable, robust and responsive.

• The deployment process for GitLab runners is developed for deployment on Kubernetes.
• A deployment process for GitLab runners is developed for deployment on VMs to service specialised shell executors (note: this will be discouraged) (this has been descoped for PI#7)
• An automated process is developed for retiring existing runners, automatically configuring new runners, and maintaining the runner registrations for existing SKA repositories.
• The existing runners merged into the Kubernetes cluster runners, and newly deployed VMs for shell executors (in the systems-team project).
• The updated deployment process for the CI/Pipeline machinery is repeatable and idempotent.
• The deployment automatically updates the global service inventory (see: SP-1061).(this has been descoped for PI#7)
• The process runs seamlessly from the management server (see: SP-1061).
• Systems Team documentation is updated to explain how to work with deployment process.