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

Author: renovate[bot]

.github/workflows/lighthouse.yml

@@ -13,7 +13,7 @@ jobs:
         ref: ${{ github.event.pull_request.head.sha }}
 
     - name: ⎔ Setup node
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v6
       with:
         node-version: 22
 

.github/workflows/linkcheck.yml

@@ -11,7 +11,7 @@ jobs:
       uses: actions/checkout@v5
 
     - name: ⎔ Setup node
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v6
       with:
         node-version: 22