feat: add support for PHPUnit 11 (#18)

Author: Chris53897

Diff for: composer.json

@@ -11,7 +11,7 @@
     ],
     "require": {
         "php": "^7.0 || ^8.0",
-        "phpunit/phpunit": "^6.5.14 || ^7.5.20 || ^8.0 || ^9.0 || ^10.0"
+        "phpunit/phpunit": "^6.5.14 || ^7.5.20 || ^8.0 || ^9.0 || ^10.0 || ^11.0.1"
     },
     "autoload": {
         "psr-4": {