Update to PHPSPec 6

Author: danmichaelo

composer.json

@@ -20,7 +20,7 @@
         "symfony/polyfill-php73": "^1.11"
     },
     "require-dev": {
-        "phpspec/phpspec": "^3.4 || ^4.0 || ^5.0",
+        "phpspec/phpspec": "^5.0 || ^6.0",
         "bossa/phpspec2-expect": "^2.1 || ^3.0",
         "wp-cli/php-cli-tools": "^0.11.1",
         "php-http/mock-client": "^1.0",