[8.x] View EngineResolver - Minor change (#39505)

Use the forget method directly.

Author: KennedyTedesco

src/Illuminate/View/Engines/EngineResolver.php

@@ -32,7 +32,7 @@ class EngineResolver
      */
     public function register($engine, Closure $resolver)
     {
-        unset($this->resolved[$engine]);
+        $this->forget($engine);
 
         $this->resolvers[$engine] = $resolver;
     }