Fixed lowest supported version of phpunit

Author: norberttech

composer.json

@@ -18,7 +18,7 @@
         "php": ">=7.2"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.5"
+        "phpunit/phpunit": "^8.5|^9.5"
     },
     "autoload": {
         "psr-4": {