chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/cloudflare-pages.yml

@@ -18,7 +18,7 @@ jobs:
     name: Publish to Cloudflare Pages
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Node
         uses: actions/setup-node@v6

.github/workflows/lint.yml

@@ -7,7 +7,7 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 24