bug: langchain.chains has been deprecated, replaced with langchain_classic.chains

Signed-off-by: RAWx18 <rawx18.dev@gmail.com>

Author: RAWx18

src/mvt/main.py

@@ -3,9 +3,9 @@
 from dotenv import load_dotenv, find_dotenv
 from langchain_mistralai.chat_models import ChatMistralAI
 from langchain_community.vectorstores import FAISS
-from langchain.chains.combine_documents import create_stuff_documents_chain
+from langchain_classic.chains.combine_documents import create_stuff_documents_chain
 from langchain_core.prompts import ChatPromptTemplate
-from langchain.chains import create_retrieval_chain
+from langchain_classic.chains import create_retrieval_chain
 from langchain_mistralai.embeddings import MistralAIEmbeddings
 #from langchain.retrievers import BM25Retriever, EnsembleRetriever
 from langchain_core.documents import Document