fix: Return inside context manager

Co-authored-by: Brett Hoerner <[email protected]>

posthog/temporal/batch_exports/postgres_batch_export.py

@@ -359,7 +359,7 @@ async def flush_to_postgres():
                 if pg_file.tell() > 0:
                     await flush_to_postgres()
 
-        return pg_file.records_total
+            return pg_file.records_total
 
 
 @workflow.defn(name="postgres-export")