Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/pages-deploy.yml

@@ -28,7 +28,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           # submodules: true