Throw Exception while using withJson method in bulk.IndexOperation

### Java API client version

9.1.5

### Java version

21

### Elasticsearch Version

9.1.5

### Problem description

Hi, I noticed this might be an issue that was reported before.
I've confirmed that it seems to be reproducible even in the latest version.
If this is an unintended error and no one is currently assigned to it, would it be okay if I try to work on it?

Code

```Java
final BulkResponse response = client.bulk(br -> br.operations(
bo -> bo.index(io -> io.withJson(jsonInputStream).index("test").id("1"))
));
```

Error
```
Class class co.elastic.clients.elasticsearch.core.bulk.IndexOperation cannot be read from JSON
java.lang.IllegalArgumentException: Class class co.elastic.clients.elasticsearch.core.bulk.IndexOperation cannot be read from JSON
at co.elastic.clients.util.WithJsonObjectBuilderBase.withJson(WithJsonObjectBuilderBase.java:46)
at co.elastic.clients.json.WithJson.withJson(WithJson.java:43)
```