Update dependency phpstan/phpstan to v2

Author: renovate[bot]

composer.json

@@ -39,7 +39,7 @@
         "github/gfm": "0.29.0",
         "michelf/php-markdown": "^1.4 || ^2.0",
         "nyholm/psr7": "^1.5",
-        "phpstan/phpstan": "^1.8.2",
+        "phpstan/phpstan": "^1.8.2 || ^2.0.0",
         "phpunit/phpunit": "^9.5.21 || ^10.5.9 || ^11.0.0",
         "scrutinizer/ocular": "^1.8.1",
         "symfony/finder": "^5.3 | ^6.0 | ^7.0",