message: schema: update IDL tests
diff: -use std::collections::HashMap;
  +use std::collections::{BTreeMap, HashMap};
  use cosmwasm_schema::{schema_for, Api, IDL_VERSION};
  use schemars::JsonSchema;
  @@ -47,7 +47,7 @@ fn test_basic_structure() {
  query: Some(schema_for!(QueryMsg)),
  migrate: Some(schema_for!(MigrateMsg)),
  sudo: Some(schema_for!(SudoMsg)),
  - responses: [("balance", schema_for!(u128))].into_iter().collect(),
  + responses: BTreeMap::from([("balance".to_string(), schema_for!(u128))]),
  }
  .render()
  .to_string()
  @@ -89,7 +89,7 @@ fn test_query_responses() {
  query: Some(schema_for!(QueryMsg)),
  migrate: None,
  sudo: None,
  - responses: [("balance", schema_for!(u128))].into_iter().collect(),
  + responses: BTreeMap::from([("balance".to_string(), schema_for!(u128))]),
  }
  .render()
  .to_string()
  