Scale gitlab-org shared runners
DRI: @rehab ### Status 2023-06-07 The [scalability saturation issue](https://gitlab.com/gitlab-com/gl-infra/capacity-planning/-/issues/560) was auto-closed :tada: - with the completion of the last issue in this epic, this can now be closed. ### Summary Currently the gitlab-org ephemeral VMs are being created in the `gitlab-ci` GCP project, we're running [out of capacity](https://gitlab.com/gitlab-com/gl-infra/capacity-planning/-/issues/560) for different metrics, including the available IPs, which was relieved temporarily in https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/16124.
epic