Fix linstor metrics node label (#1326)

Signed-off-by: Andrei Kvapil <kvapss@gmail.com>

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## What this PR does


### Release note

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```release-note
[linstor] Fix linstor metrics node label
```

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## Summary by CodeRabbit

* **Refactor**
* Updated label configuration in monitoring setup to use
"controller_node" instead of "node" for improved clarity in metrics.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/system/linstor/templates/podscrape.yaml

@@ -14,7 +14,7 @@ spec:
     - replacement: linstor-controller
       targetLabel: job
     - sourceLabels: [__meta_kubernetes_pod_node_name]
-      targetLabel: node
+      targetLabel: controller_node
     - targetLabel: tier
       replacement: cluster
   selector: