Add test to PHP 8.3 (#24)

Author: cesargb

.github/workflows/tests.yml

@@ -8,7 +8,7 @@ jobs:
         strategy:
             fail-fast: false
             matrix:
-                php: [8.2, 8.1, 8.0]
+                php: [8.3, 8.2, 8.1, 8.0]
 
         name: P${{ matrix.php }}