Update dependency phpstan/phpstan-phpunit to ^2.0.6

| datasource | package                 | from  | to    |
| ---------- | ----------------------- | ----- | ----- |
| packagist  | phpstan/phpstan-phpunit | 2.0.5 | 2.0.6 |

Author: renovate[bot]

composer.json

@@ -15,7 +15,7 @@
     },
     "require-dev": {
         "phpstan/phpstan": "^2.1.11",
-        "phpstan/phpstan-phpunit": "^2.0.5",
+        "phpstan/phpstan-phpunit": "^2.0.6",
         "phpstan/phpstan-strict-rules": "^2.0.4",
         "phpunit/phpunit": "^12.0.10",
         "slam/php-cs-fixer-extensions": "^3.12",