refactor(api): use standalone graphon package (#34209)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/core/rag/datasource/retrieval_service.py

@@ -4,6 +4,7 @@ from concurrent.futures import ThreadPoolExecutor
 from typing import Any, NotRequired
 
 from flask import Flask, current_app
+from graphon.model_runtime.entities.model_entities import ModelType
 from sqlalchemy import select
 from sqlalchemy.orm import Session, load_only
 from typing_extensions import TypedDict
@@ -24,7 +25,6 @@ from core.rag.rerank.rerank_type import RerankMode
 from core.rag.retrieval.retrieval_methods import RetrievalMethod
 from core.tools.signature import sign_upload_file
 from extensions.ext_database import db
-from graphon.model_runtime.entities.model_entities import ModelType
 from models.dataset import (
     ChildChunk,
     Dataset,

api/core/rag/datasource/vdb/vector_factory.py

@@ -4,6 +4,7 @@ import time
 from abc import ABC, abstractmethod
 from typing import Any
 
+from graphon.model_runtime.entities.model_entities import ModelType
 from sqlalchemy import select
 
 from configs import dify_config
@@ -17,7 +18,6 @@ from core.rag.models.document import Document
 from extensions.ext_database import db
 from extensions.ext_redis import redis_client
 from extensions.ext_storage import storage
-from graphon.model_runtime.entities.model_entities import ModelType
 from models.dataset import Dataset, Whitelist
 from models.model import UploadFile