Add 510 tests to PHP SDK for improved code coverage (83.62%)

Co-authored-by: clemensv <542030+clemensv@users.noreply.github.com>

Author: Copilot

php/composer.json

@@ -21,7 +21,7 @@
         "php": ">=8.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^10.0 || ^11.0"
+        "phpunit/phpunit": "*"
     },
     "autoload": {
         "psr-4": {