fix: always fully pre-import manifests once, even on retries

mentioned in commit 41a60323

mentioned in merge request gitlab-org/build/CNG!987 (merged)

mentioned in merge request gitlab-com/gl-infra/k8s-workloads/gitlab-com!1733 (merged)

mentioned in merge request gitlab-com/gl-infra/k8s-workloads/gitlab-com!1734 (merged)

mentioned in merge request omnibus-gitlab!6064 (merged)

mentioned in merge request gitlab-development-kit!2503 (merged)