fix: fetch item price in sales invoice

When create standalone sales invoice, the item price will not be created fetch.
By adding "posting_date" to dict: item_price_args, it will be fetch on building the condition of SQL.
diff --git a/erpnext/stock/get_item_details.py b/erpnext/stock/get_item_details.py
index 0ed3b27..0af018b 100644
--- a/erpnext/stock/get_item_details.py
+++ b/erpnext/stock/get_item_details.py
@@ -636,6 +636,10 @@
 	if args.get('transaction_date'):
 		conditions += """ and %(transaction_date)s between
 			ifnull(valid_from, '2000-01-01') and ifnull(valid_upto, '2500-12-31')"""
+		
+	if args.get('posting_date'):
+		conditions += """ and %(posting_date)s between
+			ifnull(valid_from, '2000-01-01') and ifnull(valid_upto, '2500-12-31')"""
 
 	return frappe.db.sql(""" select name, price_list_rate, uom
 		from `tabItem Price` {conditions}
@@ -657,6 +661,7 @@
 			"supplier": args.get('supplier'),
 			"uom": args.get('uom'),
 			"transaction_date": args.get('transaction_date'),
+			"posting_date": args.get('posting_date'),
 	}
 
 	item_price_data = 0