Add changelog entry for tokio-tungstenite upgrade (#3089)

Author: jplatte

axum-extra/CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning].
 
 # Unreleased
 
+- **breaking:** `axum::extract::ws::Message` now uses `Bytes` in place of `Vec<u8>`,
+  and a new `Utf8Bytes` type in place of `String`, for its variants ([#3078])
+- **changed:** Upgraded `tokio-tungstenite` to 0.26 ([#3078])
+
+[#3078]: https://github.com/tokio-rs/axum/pull/3078
+
 # 0.10.0
 
 ## rc.1