chore: phpstan 2.0 (#45)

Author: chr-hertel

composer.json

@@ -18,7 +18,7 @@
     },
     "require-dev": {
         "php-cs-fixer/shim": "^3.64",
-        "phpstan/phpstan": "^1.12",
+        "phpstan/phpstan": "^2.0",
         "phpunit/phpunit": "^11.3"
     },
     "config": {