fix(mqttc): mention the change in CHANGELOG

Author: bitcapybara

rumqttc/CHANGELOG.md

@@ -26,6 +26,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Replace `Vec<Option<u16>>` with `FixedBitSet` for managing packet ids of released QoS 2 publishes and incoming QoS 2 publishes in `MqttState`.
 * Accept `native_tls::TlsConnector` as input for `Transport::tls_with_config`.
 * Update `thiserror` to `2.0.8`, `tokio-rustls` to `0.26.0`, `rustls-webpki` to `0.102.8`, `rustls-pemfile` to `2.2.0`, `rustls-native-certs` to `0.8.1`, `async-tungstenite` to `0.28.0`, `ws_stream_tungstenite` to `0.14.0`, `native-tls` to `0.2.12` and `tokio-stream` to `0.1.16`.
+* Remove `request_tx` from `EventLoop` to allow gracefully exit.
 
 ### Deprecated