update phpunit to latest version

Author: transistive

Diff for: composer.json

@@ -43,7 +43,7 @@
         "composer-runtime-api": "Install composer 2 for auto detection of version in user agent"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.0",
+        "phpunit/phpunit": "^10.0",
         "nyholm/psr7": "^1.3",
         "nyholm/psr7-server": "^1.0",
         "kriswallsmith/buzz": "^1.2",