fix(openai): fix tracing exception in model response getting method when tracing is disabled

[upphiminn]

This pull request addresses a possible issue in the OpenAIResponsesModel where an exception could occur during getting a response when tracing is disabled. When tracing is disabled there is no parent trace so withResponseSpan fails with not finding a context trace for the span it attempts to create. This leads to the whole getResponse failing. Fix found below copies the same style of span creation only when tracing is enabled as seen in getStreamedResponse method.

[seratch]

This looks good to me; @dkundel-openai any concern?

[dkundel-openai]

This seems odd because if tracing is disabled there should still be a NoopTrace that this should get attached to?

[dkundel-openai]

The main thing is that not using withResponseSpan() means that we are not creating a new entry in the Async Context Store which could create race condition issues so we should avoid it wherever possible

[seratch]

@dkundel-openai thanks for the good point.
@upphiminn can you share what actually happens in this scenario? > When tracing is disabled there is no parent trace so withResponseSpan fails with not finding a context trace for the span it attempts to create.

If we figure the root cause out, the fix can be much simpler than rewriting a bunch of code.

[seratch]

to avoid confusion, let me revert the approval for now