update downgrade script

Author: samsonasik

build/target-repository/composer.json

@@ -6,7 +6,7 @@
     "require": {
         "php": "^7.4|^8.0",
         "nette/utils": "^3.2.9 || ^4.0",
-        "phpstan/phpstan": "^1.10.30",
+        "phpstan/phpstan": "^2.0",
         "webmozart/assert": "^1.11"
     },
     "autoload": {