updated php dependency

Author: mmelograno

composer.json

@@ -29,7 +29,7 @@
   },
 
   "require-dev": {
-    "phpunit/phpunit": "^9.0.0",
+    "phpunit/phpunit": "^9.6",
     "squizlabs/php_codesniffer": "3.*",
     "rogervila/php-sonarqube-scanner": "1.1.0",
     "mockery/mockery": "^1.5"