Update lineup replacement logic in load_contest_file function

- Modified the replacement method for position indicators in the cleaned dataframe to use regex, enhancing the accuracy of lineup processing.
- This change continues the effort to improve data handling and user experience within the application.

global_func/load_contest_file.py

@@ -41,7 +41,7 @@ def load_contest_file(upload, sport):
             
             # Create the cleaned dataframe with just the essential columns
             cleaned_df = df[['BaseName', 'EntryCount', 'Lineup']]
-            cleaned_df['Lineup'] = cleaned_df['Lineup'].replace(pos_list, ',')
+            cleaned_df['Lineup'] = cleaned_df['Lineup'].replace(pos_list, value=',', regex=True)
             
             # Get unique entry names
             entry_list = list(set(df['BaseName']))