fix: ignore empty customer/supplier in item query (#29610)

* fix: dont try to filter by customer/supplier if None

* test: item query with emtpy supplier

erpnext/controllers/queries.py

@@ -249,6 +249,9 @@ def item_query(doctype, txt, searchfield, start, page_len, filters, as_dict=Fals
 				del filters['customer']
 			else:
 				del filters['supplier']
+		else:
+			filters.pop('customer', None)
+			filters.pop('supplier', None)
 
 
 	description_cond = ''