Raising PHP minimum requirements to 8.1.0

Author: Hackwar

composer.json

@@ -6,7 +6,7 @@
     "homepage": "https://github.com/joomla-framework/string",
     "license": "GPL-2.0-or-later",
     "require": {
-        "php": "^7.2.5|~8.0.0|~8.1.0",
+        "php": "~8.1.0",
         "symfony/deprecation-contracts": "^2.1"
     },
     "require-dev": {