chore: upgrade dev dependencies (#418)

- allow phpunit@11
- upgrade to phpstan@2

Author: Rotzbua

composer.json

@@ -42,9 +42,9 @@
     "ext-gmp": "Optional for performance."
   },
   "require-dev": {
-    "phpunit/phpunit": "^10.5.9",
-    "phpstan/phpstan": "^1.10.57",
-    "friendsofphp/php-cs-fixer": "^v3.68.3"
+    "phpunit/phpunit": "^10.5.44|^11.5.6",
+    "phpstan/phpstan": "^2.1.2",
+    "friendsofphp/php-cs-fixer": "^v3.68.5"
   },
   "autoload": {
     "psr-4": {