Retriever is reinitialized everytime when calling swr, amr pipeline function.

[hungchiayu1]

https://github.com/Capstone-S17/DuRAG/blob/e913c16f8a6ce537140479ed0ae6c594ffa0245b/src/pipelines/rag_swr.py#L50-L63

I think it is recommended to initialize the retriever just once within a RAG pipeline class. The RAG pipeline class will store a weaviate instance and connect every time it calls the retriever

[hungchiayu1]

Fixed