PHP version bump

Author: jubbs

README.md

@@ -15,7 +15,7 @@ This branch is for use with CakePHP 5.0+. For CakePHP 4, please use cake-4.x bra
 This plugin has the following requirements:
 
 * CakePHP 5.0 or greater.
-* PHP 7.2 or greater.
+* PHP 8.1 or greater.
 
 ## Installation
 

composer.json

@@ -29,7 +29,7 @@
         "issues": "https://github.com/sprintcube/cakephp-sendgrid/issues"
     },
     "require": {
-        "php": ">=7.2",
+        "php": ">=8.1",
         "cakephp/cakephp": "^5.0.0"
     },
     "require-dev": {