Fix Kubernetes Manifest for Web UI

There are currently 2 issues with the Kubernetes manifest:

- open-webui-deployment refers to ollama-webui-pvc but not included in
  kustomization.yaml, causing issue if using GPU deployment
- ollama-webui-pvc is using the wrong namespace

This commit fixes both issue.

kubernetes/manifest/base/webui-pvc.yaml

@@ -4,7 +4,7 @@ metadata:
   labels:
     app: ollama-webui
   name: ollama-webui-pvc
-  namespace: ollama-namespace
+  namespace: open-webui
 spec:
   accessModes: ["ReadWriteOnce"]
   resources: