Merge pull request #12 from omines/renovate/actions-checkout-6.x

Update actions/checkout action to v6

Author: curry684

.github/workflows/code-quality.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ${{ fromJSON('["ubuntu-latest", "self-hosted"]')[github.repository == 'github/docs-internal'] }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Composer install
         uses: php-actions/composer@v6