Update app.py

app.py

@@ -1,6 +1,6 @@
 import streamlit as st
 import pandas as pd
-from appStore.prep_data import process_giz_worldwide, remove_duplicates
+from appStore.prep_data import process_giz_worldwide, remove_duplicates, get_max_end_year
 from appStore.prep_utils import create_documents, get_client
 from appStore.embed import hybrid_embed_chunks
 from appStore.search import hybrid_search