message: Update changelog with info about `WasmerEnv`
diff: ### Changed
  +- [#1739](https://github.com/wasmerio/wasmer/pull/1739) Environments passed to host function- must now implement the `WasmerEnv` trait. You can implement it on your existing type with `#[derive(WasmerEnv)]`.
  - [#1838](https://github.com/wasmerio/wasmer/pull/1838) Deprecate `WasiEnv::state_mut`: prefer `WasiEnv::state` instead.
  - [#1663](https://github.com/wasmerio/wasmer/pull/1663) Function environments passed to host functions now must be passed by `&` instead of `&mut`. This is a breaking change. This change fixes a race condition when a host function is called from multiple threads. If you need mutability in your environment, consider using `std::sync::Mutex` or other synchronization primitives.
  - [#1830](https://github.com/wasmerio/wasmer/pull/1830) Minimum supported Rust version bumped to 1.47.0
  