ci: downgrade to phpunit ^10.5

Author: dirx

composer.json

@@ -29,7 +29,7 @@
     "psr/http-server-handler": "^1.0"
   },
   "require-dev": {
-    "phpunit/phpunit": "^11.4"
+    "phpunit/phpunit": "^10.5"
   },
   "autoload": {
     "psr-4": {