langchain

bcd5842b - community[patch]: Updating default PPLX model to supported llama-3.1 model. (#25643)

community[patch]: Updating default PPLX model to supported llama-3.1 model. (#25643) # Issue As of late July, Perplexity [no longer supports Llama 3 models](https://docs.perplexity.ai/changelog/introducing-new-and-improved-sonar-models). # Description This PR updates the default model and doc examples to reflect their latest supported model. (Mostly updating the same places changed by #23723.) # Twitter handle `@acompa_` on behalf of the team at Not Diamond. Check us out [here](https://notdiamond.ai). --------- Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>