Bump phpunit upwards to at least 8.5

Author: wtfzdotnet

composer.json

@@ -54,7 +54,7 @@
         "symfony/cache": ">=4.4 || ^5 || ^6",
         "symfony/event-dispatcher": ">=4.4 || ^5 || ^6",
         "phpstan/phpstan": "^0.12.18",
-        "phpunit/phpunit": "^8.0 || ^9.3",
+        "phpunit/phpunit": ">=8.5 || ^9.3",
         "php-http/guzzle7-adapter": "^0.1",
         "monolog/monolog": ">=1.11.0",
         "vimeo/psalm": "^4",