chore: update composer.json for v4.5.3

and run `composer update` with PHP 8.1.

Author: kenjis

composer.json

@@ -37,6 +37,10 @@
   "minimum-stability": "dev",
   "prefer-stable": true,
   "autoload": {
+    "psr-4": {
+      "App\\": "app/",
+      "Config\\": "app/Config"
+    },
     "exclude-from-classmap": [
       "**/Database/Migrations/**"
     ]