Update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/lighthouse.yml

@@ -8,7 +8,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Setup Node.js
-        uses: actions/setup-node@v5
+        uses: actions/setup-node@v6
         with:
           node-version: '22'
 

.github/workflows/playwright.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v5
-    - uses: actions/setup-node@v5
+    - uses: actions/setup-node@v6
       with:
         node-version: 22
     - name: Install dependencies

.github/workflows/repomix.yml

@@ -26,7 +26,7 @@ jobs:
           sleep 300
 
       - name: Setup Node.js
-        uses: actions/setup-node@v5
+        uses: actions/setup-node@v6
         with:
           node-version: "22"