chore: move rector from require-dev to require

Author: kenjis

composer.json

@@ -34,12 +34,12 @@
         "phpstan/phpstan-phpunit": "^1.0",
         "phpunit/phpunit": "^9.3",
         "roave/security-advisories": "dev-latest",
-        "vimeo/psalm": "^5.0"
+        "vimeo/psalm": "^5.0",
+        "rector/rector": "^0.18.3"
     },
     "require-dev": {
         "codeigniter4/framework": "^4.1",
-        "icanhazstring/composer-unused": "^0.8.2",
-        "rector/rector": "0.18.3"
+        "icanhazstring/composer-unused": "^0.8.2"
     },
     "minimum-stability": "dev",
     "prefer-stable": true,