[FIX] sale: singleton error when validating payments

- When validating a payment an "expected singleton" exception is
raised due to the fact that we are using a recordset with multiple
record instead of a recordset with a single record.

OPW-1981632

closes odoo/odoo#33767

Signed-off-by: Christophe Simonis <chs@odoo.com>

addons/sale/models/payment.py

@@ -96,11 +96,11 @@ class PaymentTransaction(models.Model):
         if self.env['ir.config_parameter'].sudo().get_param('sale.automatic_invoice'):
             default_template = self.env['ir.config_parameter'].sudo().get_param('sale.default_email_template')
             if default_template:
-                ctx_company = {'company_id': self.acquirer_id.company_id.id,
-                               'force_company': self.acquirer_id.company_id.id,
-                               'mark_invoice_as_sent': True,
-                               }
                 for trans in self.filtered(lambda t: t.sale_order_ids):
+                    ctx_company = {'company_id': trans.acquirer_id.company_id.id,
+                                   'force_company': trans.acquirer_id.company_id.id,
+                                   'mark_invoice_as_sent': True,
+                                   }
                     trans = trans.with_context(ctx_company)
                     for invoice in trans.invoice_ids:
                         invoice.message_post_with_template(int(default_template), notif_layout="mail.mail_notification_paynow")
@@ -109,9 +109,9 @@ class PaymentTransaction(models.Model):
     @api.multi
     def _invoice_sale_orders(self):
         if self.env['ir.config_parameter'].sudo().get_param('sale.automatic_invoice'):
-            ctx_company = {'company_id': self.acquirer_id.company_id.id,
-                           'force_company': self.acquirer_id.company_id.id}
             for trans in self.filtered(lambda t: t.sale_order_ids):
+                ctx_company = {'company_id': trans.acquirer_id.company_id.id,
+                               'force_company': trans.acquirer_id.company_id.id}
                 trans = trans.with_context(**ctx_company)
                 trans.sale_order_ids._force_lines_to_invoice_policy_order()
                 invoices = trans.sale_order_ids.action_invoice_create()