Doc: Added missing ctx.Drop() to whats_new.md

Author: aliziyacevik

docs/whats_new.md

@@ -342,6 +342,7 @@ testConfig := fiber.TestConfig{
 - **ViewBind**: Binds data to a view, replacing the old `Bind` method.
 - **CBOR**: Introducing [CBOR](https://cbor.io/) binary encoding format for both request & response body. CBOR is a binary data serialization format which is both compact and efficient, making it ideal for use in web applications.
 - **End**: Similar to Express.js, immediately flushes the current response and closes the underlying connection.
+- **Drop**: Terminates the client connection silently without sending any HTTP headers or response body. This can be used for scenarios where you want to block certain requests without notifying the client, such as mitigating DDoS attacks or protecting sensitive endpoints from unauthorized access.
 
 ### Removed Methods