Add version history to Harbor docs

doc/user/project/integrations/harbor.md

@@ -6,6 +6,8 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 
 # Harbor container registry integration **(FREE)**
 
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/80999) in GitLab 14.9.
+
 Use Harbor as the container registry for your GitLab project.
 
 [Harbor](https://goharbor.io/) is an open source registry that can help you manage artifacts across cloud native compute platforms, like Kubernetes and Docker.