Bump minimum PHP to 8.3 for Laravel 13 compatibility

Co-authored-by: chinleung <19669331+chinleung@users.noreply.github.com>

Author: Copilot

.github/workflows/tests.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        php: ['8.2', '8.3', '8.4']
+        php: ['8.3', '8.4']
         stability: [prefer-lowest, prefer-stable]
 
     steps:

composer.json

@@ -19,7 +19,7 @@
         }
     ],
     "require": {
-        "php": "^8.2",
+        "php": "^8.3",
         "chinleung/laravel-locales": "^2.0",
         "illuminate/support": "^12.0|^13.0"
     },