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

Author: renovate[bot]

.github/workflows/lighthouse.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       - name: Use Node.js 22.x
-        uses: actions/setup-node@v5
+        uses: actions/setup-node@v6
         with:
           node-version: 22.x
       # Build needs around 400 seconds on Netlify.