Bump PHPStan to 2.0

https://github.com/contributte/phpstan/releases/tag/v0.2.0

Author: jtojnar

composer.json

@@ -21,7 +21,7 @@
     "nette/di": "^3.1.0",
     "latte/latte": "^3.0.0",
     "contributte/qa": "^0.3",
-    "contributte/phpstan": "^0.1",
+    "contributte/phpstan": "^0.2",
     "webchemistry/testing-helpers": "^4.0.0"
   },
   "conflict": {