Remove row count probes used for registry migration
These queries were previously enabled to support Deploy and migrate the new container registry f... (gitlab-org&5523 - closed). We're now removing all the related code and these queries can go. All the depending dashboards and alerts have been removed in gitlab-com/runbooks!5513 (merged).
We've disabled these probes previously in https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/3424 and https://gitlab.com/gitlab-com/gl-infra/chef-repo/-/merge_requests/3425.
Related to gitlab-org/gitlab#410163 (closed).