Update PHPUnit 8.x & 9.x to fix PHPUnit Vulnerability (#167)

Author: marc-mabe

composer.json

@@ -23,7 +23,7 @@
     "require-dev": {
         "phpbench/phpbench": "^0.16.10 || ^1.0.4",
         "phpstan/phpstan": "^1.3.1",
-        "phpunit/phpunit": "^7.5.20 | ^8.5.22 | ^9.5.11",
+        "phpunit/phpunit": "^7.5.20 | ^8.5.52 | ^9.6.33",
         "vimeo/psalm": "^4.17.0 | ^5.26.1"
     },
     "autoload": {