Update dependency wyrihaximus/async-test-utilities to v8

Author: renovate[bot]

composer.json

@@ -21,7 +21,7 @@
         "wyrihaximus/react-event-loop-rx-scheduler-hook-up": "^0.1.1"
     },
     "require-dev": {
-        "wyrihaximus/async-test-utilities": "^5 || ^7.2",
+        "wyrihaximus/async-test-utilities": "^5 || ^7.2 || ^8.0",
         "wyrihaximus/ticking-promise": "^3"
     },
     "autoload": {