Add php8 support

Author: Zerogiven

composer.json

@@ -35,7 +35,7 @@
         "issues": "https://github.com/CSoellinger/silverstripe-rollbar/issues"
     },
     "require": {
-        "php": "~7.3,<=8.1",
+        "php": ">=7.3 <8.2",
         "rollbar/rollbar": "^2.1",
         "silverstripe/framework": "~4.10"
     },