Kubernetes Labeling: git nodepools have the incorrect type label

• Part of: All kubernetes resources should have labels matching our Prometheus label taxonomy: &687 (closed)

1. Ensure that git nodepools have the correct stage labels
2. Ensure that the git nodepools have the correct type labels (git)
3. Ensure that the git nodepools have the correct shard labels (git-ssh, git-https)
4. Update the metrics catalog kubeConfig.labelSelectors definition for the service: https://gitlab.com/gitlab-com/runbooks/blob/master/metrics-catalog/services/git.jsonnet#L63-73