Refactor import of `SimpleDirectoryReader` in `hf_submission_api` to optimize placement.

src/gaia_solving_agent/hf_submission_api.py

@@ -3,6 +3,7 @@ from functools import lru_cache
 
 import pandas as pd
 import requests
+from llama_index.core import SimpleDirectoryReader
 from llama_index.core.agent.workflow import BaseWorkflowAgent
 from workflows import Workflow
 
@@ -54,7 +55,6 @@ def fetching_questions(api_url: str = DEFAULT_API_URL):
 async def run_agent(agent, questions_data):
     results_log = []
     answers_payload = []
-    from llama_index.core import SimpleDirectoryReader
 
     # First, ensure that all complementary files are in the FILE_DIR
     for item in questions_data: