Update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/angular-build.yml

@@ -28,7 +28,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: 'Setup Node.js 18.x'
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: '18.x'
           cache: 'npm'