Support PHP 8 for sebastianbergmann/phpunit#4325

Author: sebastianbergmann

composer.json

@@ -29,7 +29,7 @@
     "prefer-stable": true,
     "minimum-stability": "dev",
     "require": {
-        "php": "^7.3",
+        "php": "^7.3 || ^8.0",
         "ext-dom": "*",
         "ext-xmlwriter": "*",
         "phpunit/php-file-iterator": "^3.0",