chore: add procedure to enable vpc_v3 in older kapsule clusters

Author: louisportay

pages/kubernetes/how-to/manage-allowed-ips.mdx

@@ -22,6 +22,9 @@ The default entry `0.0.0.0/0` enables any host to establish a connection.
 - A Scaleway account logged into the [Scaleway console](https://console.scaleway.com)
 - [Owner](/iam/concepts/#owner) status or [IAM permissions](/iam/concepts/#permission) allowing actions in the intended Organization
 - [Created](/kubernetes/how-to/create-cluster) a Kubernetes Kapsule or Kosmos cluster
+<Message type="tip">
+  Every cluster created after March 8th have this feature enabled by default, you can check if your cluster have it by looking in the console: You should see a `Network` tab in your cluster view. If this is not the case, you can open a support ticket to have it enabled manually.
+</Message>
 
 <Message type="note">
   Allowed IP configuration is available for [fully isolated Kapsule clusters](/kubernetes/reference-content/secure-cluster-with-private-network/#what-is-the-difference-between-controlled-isolation-and-full-isolation), and Kosmos clusters.