Product Area: Azure Magaged Grafana users remain after being removed from IAM in the portal

### What happened? A person on our team left five months ago, internally transferring to another microsoft org (which means the user is still in Entra ID). I just noticed that this user has admin access to our grafana instance. I found this odd because I know that he was removed from the security group that provided him with access when he left. I try to remove/reduce role, or delete user in grafana and I get a message that I need to do this in the portal in IAM. In the portal, I check this user's access, and I see no access in IAM (because he has been removed from the security group). I have no way of removing or reducing this user's access. This is just one example, there are others (with Viewer roles) that have left our org that I cannot remove their access in Grafana even though they don't show that they have access in Azure portal IAM ### What did you expect to happen? I expected that users that no longer have access in the portal (in IAM) would no longer have access in the Users section of Administration in grafana. ### Did this work before? Not that I'm aware of. We have limited users in grafana, and until recently none had left the org ### How do we reproduce it? 1.Tried to delete three different users that have left recently, in Administration in grafana. 2. All three messages were to do this in the portal in IAM 3. For all three users, the Check Access in the portal IAM section showed no access, but in grafana Admin/Users, all three still showed having access, 1 in Admin role, and two in Viewer role. ### Is the bug inside a dashboard panel? No ### Environment (with versions)? Grafana: 11.6.3 OS: Azure Browser: Microsoft Edge ### Grafana platform? Other ### Datasource(s)? N/A