`litellm` embedding and chat spans missing

[alexander-alderman-webb]

#5343

Investigate why litellm.input_callback, litellm.success_callback and litellm.failure_callback are not triggered in the scripts used by https://github.com/getsentry/testing-ai-sdk-integrations.

Decide if we should add patches in addition to the hooks provided by the library, or if we should open an issue in litellm (if it's a quick fix to add the relevant hooks in the call paths the testing framework invokes).

[linear]

PY-2099