fix: allow to change rate manually in case of stand-alone credit note (#27036)

Co-authored-by: Marica <maricadsouza221197@gmail.com>
diff --git a/erpnext/stock/stock_ledger.py b/erpnext/stock/stock_ledger.py
index eddd048..27feec1 100644
--- a/erpnext/stock/stock_ledger.py
+++ b/erpnext/stock/stock_ledger.py
@@ -332,6 +332,7 @@
 			where
 				item_code = %(item_code)s
 				and warehouse = %(warehouse)s
+				and is_cancelled = 0
 				and timestamp(posting_date, time_format(posting_time, %(time_format)s)) = timestamp(%(posting_date)s, time_format(%(posting_time)s, %(time_format)s))
 
 			order by