phpunit updated.

Author: syslogic

composer.json

@@ -40,7 +40,7 @@
     "guzzlehttp/psr7": "^2.4.3"
   },
   "require-dev": {
-    "phpunit/phpunit": "^9.5.27",
+    "phpunit/phpunit": "^9.5.28",
     "google/cloud-tools": "^0.13.0"
   },
   "autoload": {