Update GitHub workflows

Author: javihgil

.github/workflows/phpmd.yml

@@ -38,7 +38,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
 
       - name: Setup PHP
         uses: shivammathur/setup-php@aa1fe473f9c687b6fb896056d771232c0bc41161