feat(setup-magento): align with upstream defaults (#355)

Co-authored-by: Herve Tribouilloy <herve@digitalrisedorset.co.uk>

Author: digitalrisedorset

setup-magento/action.yml

@@ -5,7 +5,7 @@ description: "This action sets up a Magento instance for further actions like ru
 inputs:
   php-version:
     description: "Setup PHP version."
-    default: "8.3"
+    default: "8.4"
     required: true
 
   tools:
@@ -27,7 +27,7 @@ inputs:
 
   magento_version: 
     required: false
-    default: '~2.4.7-p4'
+    default: '~2.4.8-p3'
     description: "The version of Magento to use. This is only relevant if you are testing an extension."
 
   apply_fixes: