Fix PHP 8.1 compatibility

Signed-off-by: Witold Wasiczko <witold@wasiczko.pl>

Author: snapshotpl

composer.json

@@ -43,7 +43,7 @@
         "laminas/laminas-coding-standard": "~2.3.0",
         "laminas/laminas-db": "^2.8.1",
         "phpspec/prophecy-phpunit": "^2.0",
-        "phpunit/phpunit": "^9.3",
+        "phpunit/phpunit": "^9.5.10",
         "psalm/plugin-phpunit": "^0.16.0",
         "vimeo/psalm": "^4.7"
     },