doc(sdk): Add #5047.

Author: Hywan

crates/matrix-sdk/CHANGELOG.md

@@ -46,6 +46,10 @@ All notable changes to this project will be documented in this file.
 - `Room::decrypt_event()` now requires an extra `matrix_sdk::Room::PushContext` parameter to
   compute the push notifications for the decrypted event.
   ([#4962](https://github.com/matrix-org/matrix-rust-sdk/pull/4962))
+- `SlidingSyncRoom` has been removed. With it, the `SlidingSync::get_room`,
+  `get_all_rooms`, `get_rooms`, `get_number_of_rooms`, and
+  `FrozenSlidingSync` methods and type have been removed.
+  ([#5047](https://github.com/matrix-org/matrix-rust-sdk/pull/5047))
 
 ## [0.11.0] - 2025-04-11