Merge pull request #8 from reactphp-parallel/renovate/major-phpunit

Update dependency wyrihaximus/async-test-utilities to v8

Author: WyriHaximus

composer.json

@@ -14,7 +14,7 @@
         "wyrihaximus/pool-info": "^2"
     },
     "require-dev": {
-        "wyrihaximus/async-test-utilities": "^7.2"
+        "wyrihaximus/async-test-utilities": "^7.2 || ^8.0"
     },
     "autoload": {
         "psr-4": {