[ML 9.3] Add `late_chunking` parameter for JinaAI task settings

[kosabogi]

Related dev PR: elastic/elasticsearch#137263

JinaA task_settings object now supports a new boolean setting: late_chunking.

Add this new parameter to the API documentation.

More info: https://docs.google.com/document/d/1ObKSCEJlucp1a3j5iz657aYNqvEvhIoGDRhV5MdYK5Q/edit?tab=t.0