chore: bump min php vers (#147)

Author: atymic

composer.json

@@ -26,7 +26,7 @@
         }
     ],
     "require": {
-        "php": "^7.2.0|^8.0|^8.1",
+        "php": "^8.0",
         "berkayk/onesignal-laravel": "^1.0.0",
         "illuminate/notifications": "5.*|^6.0|^7.0|^8.0|^9.0|^10.0",
         "illuminate/support": "5.*|^6.0|^7.0|^8.0|^9.0|^10.0"