fix(xcm): use single encoding for XCM messages

crates/env/src/engine/on_chain/impls.rs

@@ -735,8 +735,8 @@ impl TypedEnvBackend for EnvInstance {
  {
  let mut scope = self.scoped_buffer();
 
- // Double encoding the message as the host fn expects an encoded message.
- let enc_msg = scope.take_encoded(&scale::Encode::encode(msg));
+ let enc_msg = scope.take_encoded(msg);
+
  #[allow(deprecated)]
  ext::xcm_execute(enc_msg).map_err(Into::into)
  }
@@ -755,8 +755,7 @@ impl TypedEnvBackend for EnvInstance {
  scope.append_encoded(dest);
  let enc_dest = scope.take_appended();
 
- // Double encoding the message as the host fn expects an encoded message.
- scope.append_encoded(&scale::Encode::encode(msg));
+ scope.append_encoded(msg);
  let enc_msg = scope.take_appended();
  #[allow(deprecated)]
  ext::xcm_send(enc_dest, enc_msg, output.try_into().unwrap())?;