Fix --prefer-lowest CI checks

Author: mmoll

composer.json

@@ -36,6 +36,7 @@
         "phpstan/phpstan-strict-rules": "^1.6",
         "phpunit/phpunit": "^8.5.36 || ^9.6.15",
         "psalm/plugin-phpunit": "^0.19",
+        "sabre/event": "^5.1.6",
         "vimeo/psalm": "^6.0.0"
     },
     "config": {