Update azure/k8s-set-context action to v4

| datasource  | package               | from | to |
| ----------- | --------------------- | ---- | -- |
| github-tags | azure/k8s-set-context | v1   | v4 |

Author: renovate[bot]

.github/workflows/forms-backend.yml

@@ -108,7 +108,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Authenticate with Kubernetes
-        uses: azure/k8s-set-context@v1
+        uses: azure/k8s-set-context@v4
         with:
           method: kubeconfig
           kubeconfig: ${{ secrets.KUBECONFIG }}