DEP Limit PHP support for CMS 6 (#549)

Author: GuySartorelli

composer.json

@@ -19,7 +19,7 @@
         }
     ],
     "require": {
-        "php": "^8.1",
+        "php": "^8.3",
         "silverstripe/cms": "^6",
         "silverstripe/framework": "^6",
         "silverstripe/admin": "^3",