Fix: Ensure CPU is set as default device when CUDA is not used

Signed-off-by: Palaniappan R <palaniappan.r.mail@gmail.com>

Author: palaniappan-r

backend/src/vectorstores/faiss.py

@@ -31,7 +31,7 @@ def __init__(
     ):
         self.embeddings_model_name = embeddings_model_name
 
-        model_kwargs = {"device": "cuda"} if use_cuda else {}
+        model_kwargs = {"device": "cuda"} if use_cuda else {"device": "cpu"}
 
         self.embedding_model: Union[
             HuggingFaceEmbeddings, GoogleGenerativeAIEmbeddings, VertexAIEmbeddings