chore(deps): update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/pr-preview.yml

@@ -333,7 +333,7 @@ jobs:
           done
 
       - name: Setup Node.js
-        uses: actions/setup-node@v5
+        uses: actions/setup-node@v6
         with:
           node-version: '24'
 

.github/workflows/pre-commit.yml

@@ -25,7 +25,7 @@ jobs:
           python-version: "3.13"
       - name: Format python code with black
         uses: psf/black@stable
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 24
           cache: "npm"

.github/workflows/visual-diff.yml

@@ -105,7 +105,7 @@ jobs:
           timeout 60 bash -c 'until curl -f http://localhost:8081/actuator/health 2>/dev/null; do sleep 2; done' || echo "Main version health check failed"
 
       - name: Setup Node.js
-        uses: actions/setup-node@v5
+        uses: actions/setup-node@v6
         with:
           node-version: '24'