Update phpunit/phpunit requirement from ^5.7 | ^6.0 | ^7.0 | ^8.0 | ^…

…9.0 to ^11.5.1

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

composer.json

@@ -60,7 +60,7 @@
   },
   "require-dev": {
     "ext-curl": "*",
-    "phpunit/phpunit": "^5.7 | ^6.0 | ^7.0 | ^8.0 | ^9.0",
+    "phpunit/phpunit": "^11.5.1",
     "phpunit/php-invoker": "*",
     "phpmd/phpmd": "@stable",
     "squizlabs/php_codesniffer": "3.*@stable",