[FIX] account_check_printing: multiple partners

- Create a bill for partner A of an amount X
- Create a bill for partner B of an amount Y
- Validate both bills
- Select both and register a payment by check.

Two payments are created with the same amount in words: X + Y.

In this specific case, we recompute the amount in words automatically.

note: this commit reintroduce the fix c52b18e65 which was lost after
changes in 10.0 (line was removed then brought back with 416d07f0b).

opw-805842
closes #24569

addons/account_check_printing/models/account_payment.py

@@ -32,7 +32,7 @@ class AccountRegisterPayments(models.TransientModel):
         res = super(AccountRegisterPayments, self)._prepare_payment_vals(invoices)
         if self.payment_method_id == self.env.ref('account_check_printing.account_payment_method_check'):
             res.update({
-                'check_amount_in_words': self.check_amount_in_words,
+                'check_amount_in_words': self.currency_id.amount_to_text(res['amount']) if self.multi else self.check_amount_in_words,
             })
         return res