[K8S Dogfooding] Deploy a Runner to run helm chart jobs

After [K8S Dogfooding] Extend GRIT to allow for more ... (gitlab-org/ci-cd/runner-tools/grit#129 - closed) • Georgi N. Georgiev | GitLab • 18.2 we will be unblocked to deploy multiple runners per operator in a cluster.

Chart is a relatively small target to start with, with only a few jobs.