Update phpstan to ^2.1 and fix reported issues

Author: JanTvrdik

composer.json

@@ -12,7 +12,7 @@
     ],
     "require": {
         "php": "^7.4 || ^8.0",
-        "phpstan/phpstan": "^2.1.8"
+        "phpstan/phpstan": "^2.1.32"
     },
     "require-dev": {
         "ergebnis/composer-normalize": "^2.45.0",