message: Add CHANGELOG entry for serde-json-wasm upgrade [skip ci]
diff: @@ -6,6 +6,13 @@ and this project adheres to
  ## [Unreleased]
  +### Fixed
  +
  +- cosmwasm-std: Upgrade `serde-json-wasm` to 0.4.0 to fix u128/i128
  + serialization of `to_vec`/`to_binary` in some cases ([#1297]).
  +
  +[#1297]: https://github.com/CosmWasm/cosmwasm/pull/1297
  +
  ### Added
  - cosmwasm-std: Implement `checked_multiply_ratio` for
  