Deprecate openstack heat (#5670)

* Fix typo in pod preset conflict example

Move container port definition to the correct line.

* Highlight openstack-heat provider deprecation

The openstack-heat provider for kube-up is being deprecated and will be
removed in a future release.

docs/tasks/inject-data-application/podpreset.md

@@ -526,10 +526,10 @@ spec:
         - mountPath: /cache
           name: cache-volume
       ports:
+        - containerPort: 80
   volumes:
     - name: cache-volume
       emptyDir: {}
-        - containerPort: 80
 ```
 
 **If we run `kubectl describe...` we can see the event:**