Update azure-arc-enable-cluster.md

Author: Greedygre

articles/container-apps/azure-arc-enable-cluster.md

@@ -47,7 +47,6 @@ Install the following Azure CLI extensions.
 az extension add --name connectedk8s --upgrade --yes
 az extension add --name k8s-extension --upgrade --yes
 az extension add --name customlocation --upgrade --yes
-az extension remove --name containerapp
 az extension add --name containerapp  --upgrade --yes
 ```