Performance OpenAPI-4.0 Regression.

[jdmcclur]

I have a primitive test hitting the /openapi endpoint. I am seeing a decent throughput regression hitting this endpoint with OpenAPI-4.0 compared to the previous version of the OpenAPI specification. Java profiles haven't made the problem obvious, but I think it may be related to how the JSON is being generated in smallrye, which is different than before.

I think this is low-impact to customers as they won't be accessing this endpoint near as much as this primitive test is doing, but it is something we test, so we need to at least understand it better. However, with other work being prioritized higher, I am not sure how soon I'll be able to work more on this.