Spring-ai Use ObjectMapper with FAIL_ON_UNKNOWN_PROPERTIES false during error handling

Some OpenAI compatible servers have unknown properties in the error response, so it is better to use an existing ObjectMapper in the ErrorHandler.

Comment From: markpollack

Good catch, I fixed this in another spot in the code base that was recently added as I cut-n-paste error from this code.

Thanks!

Comment From: markpollack

I found some more places as well. Will be reviewing.