Kubecost: Review / update "shared" kubecost resources

[vexingly]

Namespaces which host platform services used by all users need to be identified by kubecost so the costs can be shared with user/project namespaces.

https://kubecost.aaw.cloud.statcan.ca/settings.html Current list: aad-pod-identity-system,boathouse-system,cert-manager-system,daaas-system,gatekeeper-system,goofys-injector-system,istio-operator-system,istio-system,jfrog-system,kube-system,kubecost-system,minio-opa-system,minio-operator-system,minio-premium-system,minio-standard-system,prometheus-system,statcan-system,vault-agent-system,velero-system

We should review this list to make sure that it is still accurate, add any new services which may exist.

Not positive in which repo it is currently being set (currently a gitlab variable), the lowest level should be here: https://gitlab.k8s.cloud.statcan.ca/cloudnative/aaw/terraform-advanced-analytics-workspaces-infrastructure/-/blob/main/variables.tf