fix: Use set instead of db_set as it is called from validate (#34967)

fix: Use set instead of db_set as it is called from validate (#34967)

(cherry picked from commit 72b5c1f70a)

Co-authored-by: Nabin Hait <nabinhait@gmail.com>

erpnext/crm/doctype/opportunity/opportunity.py

@@ -60,7 +60,7 @@ class Opportunity(TransactionBase, CRMNote):
 			if not self.get(field) and frappe.db.field_exists(self.opportunity_from, field):
 				try:
 					value = frappe.db.get_value(self.opportunity_from, self.party_name, field)
-					self.db_set(field, value)
+					self.set(field, value)
 				except Exception:
 					continue