fix: enforce single access record for import route auth tokens

mentioned in commit 1f2007c8

mentioned in merge request gitlab-org/build/CNG!913 (merged)

mentioned in merge request omnibus-gitlab!5944 (merged)

mentioned in merge request gitlab-org/charts/gitlab!2423 (merged)

mentioned in merge request gitlab-com/gl-infra/k8s-workloads/gitlab-com!1566 (merged)

mentioned in merge request gitlab-com/gl-infra/k8s-workloads/gitlab-com!1567 (merged)