Add Pinecone filter support to fromExistingIndex when using Python

[kulaone]

When using PineconeStore.fromExistingIndex with JS there is a way to add Pinecone filter to store.

  const vectorStore = await PineconeStore.fromExistingIndex(
      new OpenAIEmbeddings(),
      { pineconeIndex, filter, namespace: NAMESPACE}
    );

However, when using Pinecone.from_existing_index with Python, there is no way to add the filter to the store. Therefore, I cannot use a filter in ConversationalRetrievalChain.