refactor: remove unused code in external repo

GitOrigin-RevId: 2631e1df0833bbcb575e3f4accd7748fc90d2d9f
diff --git a/src/core.php b/src/core.php
index 0e563e2..086bf58 100644
--- a/src/core.php
+++ b/src/core.php
@@ -20,7 +20,6 @@
 
 // Core of the application
 
-const INTERNAL_CLASS_NAMESPACE = "Internal\\";
 
 // Classes autoload
 spl_autoload_register(function($className) {