fix: Removes debug output from form submission

Eliminates unnecessary print_r function call for form data,
enhancing code clarity and preventing potential data exposure
during form submission handling.

index.php

@@ -67,7 +67,6 @@ if ($mform->is_cancelled()) {
     // Handle form cancellation, if necessary
     redirect(new moodle_url('/admin/report.php'));
 } else if ($data = $mform->get_data()) {
-    print_r($data);
     $userid = $data->userid;
 
     // Fetch and display user grades if a user is selected