Update helpers.md (#10681)

* Update helpers.md

If you have the swoole PHP extension installed, Laravel's defer() helper may conflict with the global defer() provided by Swoole. Would be great to have this warning in the docs.

* Update helpers.md

---------

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

Author: Sairahcaz

helpers.md

@@ -3224,6 +3224,9 @@ By default, deferred functions will only be executed if the HTTP response, Artis
 defer(fn () => Metrics::reportOrder($order))->always();
 ```
 
+> [!WARNING]
+> If you have the **swoole** PHP extension installed, Laravel's `defer` function may conflict with Swoole's own global `defer` function, leading to web server errors. Make sure you call Laravel's `defer` helper by explicitly namespacing it: `use function Illuminate\Support\defer;`
+
 <a name="cancelling-deferred-functions"></a>
 #### Cancelling Deferred Functions