Update facade docblocks

Author: taylorotwell

src/Illuminate/Support/Facades/App.php

@@ -130,6 +130,7 @@
  * @method static void afterResolving(\Closure|string $abstract, \Closure|null $callback = null)
  * @method static void afterResolvingAttribute(string $attribute, \Closure $callback)
  * @method static void fireAfterResolvingAttributeCallbacks(\ReflectionAttribute[] $attributes, mixed $object)
+ * @method static string|null currentlyResolving()
  * @method static array getBindings()
  * @method static string getAlias(string $abstract)
  * @method static void forgetExtenders(string $abstract)