[9.x] Add docs for pushQuietly method (#8547)

* Add pushQuietly method

* Update eloquent-relationships.md

---------

Co-authored-by: Valodia <[email protected]>
Co-authored-by: Taylor Otwell <[email protected]>

Author: 3 people

eloquent-relationships.md

@@ -1860,6 +1860,10 @@ If you would like to `save` your model and all of its associated relationships,
 
     $post->push();
 
+The `pushQuietly` method may be used to save a model and its associated relationships without raising any events:
+
+    $post->pushQuietly();
+
 <a name="the-create-method"></a>
 ### The `create` Method