OpenAI chat.completions.parse and Anthropic messages.parse produce no span #7891

Version

2.71.0 (master @ 6a4eb20)

Steps to Reproduce

Call client.chat.completions.parse(model=..., messages=..., response_format=MyModel) (sync or async), or Anthropic client.messages.parse(...).

Expected Result

A gen_ai.chat span with token usage, like create().

Actual Result

No span, so structured-output calls are invisible. parse() calls self._post directly instead of create(), and only create and stream are patched (openai.py#L138-L149, anthropic.py#L245-L274). responses.parse is the same gap (#5401). Checked on openai 1.109.1 to 3.24.0 and anthropic 0.125.0 to 1.11.0.

I'd like to open a PR to fix this, with tests, if that's okay with you.