Add October CMS 3.x to supported versions

Author: adrenth

composer.json

@@ -14,7 +14,7 @@
     },
     "require": {
         "php": "^7.4 || ^8.0",
-        "october/system": "^1.0 || ^2.0",
+        "october/system": "^1.0 || ^2.0 || ^3.0",
         "composer/installers": "^1.0 || ^2.0"
     },
     "archive": {