PHPStan is not true dependency (#3)

Author: janedbal

composer.json

@@ -13,13 +13,13 @@
         "error identifier"
     ],
     "require": {
-        "php": "^8.1",
-        "phpstan/phpstan": "^2"
+        "php": "^8.1"
     },
     "require-dev": {
         "editorconfig-checker/editorconfig-checker": "^10.7.0",
         "ergebnis/composer-normalize": "2.47.0",
         "phpstan/extension-installer": "^1.4.3",
+        "phpstan/phpstan": "^2.1.17",
         "phpstan/phpstan-phpunit": "^2.0.6",
         "phpstan/phpstan-strict-rules": "^2.0.4",
         "phpunit/phpunit": "^10.5.46",