Remove unneeded code

The engine is type hinted in `Configure::config()`.

src/Core/Configure.php

@@ -299,9 +299,6 @@ class Configure
         if (!$engine) {
             throw new Exception(sprintf('There is no "%s" config engine.', $config));
         }
-        if (!method_exists($engine, 'dump')) {
-            throw new Exception(sprintf('The "%s" config engine, does not have a dump() method.', $config));
-        }
         $values = static::$_values;
         if (!empty($keys) && is_array($keys)) {
             $values = array_intersect_key($values, array_flip($keys));