Make partner_generic reference fail gracefully if not found

Updated the code to handle the case where the generic partner reference is missing by adding `raise_if_not_found=False`. This ensures the process does not crash and improves robustness in scenarios where the reference is unavailable.

deltatech_expenses/models/deltatech_expenses_deduction.py

@@ -325,7 +325,7 @@ def validate_expenses(self):
         purchase_journal = self.env["account.journal"].search(domain, limit=1)
         partner_generic = self.company_id.generic_partner_id
         if not partner_generic:
-            partner_generic = self.env.ref("deltatech_partner_generic.partner_generic")
+            partner_generic = self.env.ref("deltatech_partner_generic.partner_generic", raise_if_not_found=False)
 
         for expenses in self:
             name = expenses.number