Start testing on PHP 8.3

Author: tvdijen

.github/workflows/php.yml

@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         operating-system: [ubuntu-latest, windows-latest]
-        php-versions: ['7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2']
+        php-versions: ['7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
 
     steps:
       - name: Setup PHP, with composer and extensions