Update phpunit/phpunit requirement from ^9.0||^7.0 to ^11.5.6

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

composer.json

@@ -28,7 +28,7 @@
         "backpack/crud": "^4.0|^5.0|^6.0"
     },
     "require-dev": {
-        "phpunit/phpunit" : "^9.0||^7.0",
+        "phpunit/phpunit" : "^11.5.6",
         "scrutinizer/ocular": "~1.1"
     },
     "autoload": {