[FIX] l10n_ar: add afip responsability for demo partner

Part of task 2124952

Populate fields that are required and added in dependencies of l10n_ar.

Remove an unused variable too as an act of kindness.

addons/l10n_ar/__init__.py

@@ -2,3 +2,4 @@
 
 from . import models
 from . import report
+from . import demo

addons/l10n_ar/demo/__init__.py

@@ -0,0 +1,3 @@
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from . import account_demo

addons/l10n_ar/demo/account_demo.py

@@ -0,0 +1,42 @@
+# -*- coding: utf-8 -*-
+import logging
+
+from odoo import api, models
+
+_logger = logging.getLogger(__name__)
+
+
+class AccountChartTemplate(models.Model):
+    _inherit = "account.chart.template"
+
+    @api.model
+    def _get_demo_data(self):
+        ref = self.env.ref
+
+        # Do not load generic demo data on these companies
+        ar_demo_companies = (
+            ref('l10n_ar.company_mono', raise_if_not_found=False),
+            ref('l10n_ar.company_exento', raise_if_not_found=False),
+            ref('l10n_ar.company_ri', raise_if_not_found=False),
+        )
+        if self.env.company in ar_demo_companies:
+            return []
+
+        yield ('res.partner', {
+            'base.res_partner_12': {
+                'l10n_ar_afip_responsibility_type_id': ref('l10n_ar.res_IVARI').id,
+            },
+            'base.res_partner_2': {
+                'l10n_ar_afip_responsibility_type_id': ref('l10n_ar.res_IVARI').id,
+            },
+        })
+        for model, data in super()._get_demo_data():
+            yield model, data
+
+    @api.model
+    def _get_demo_data_move(self):
+        cid = self.env.company.id
+        model, data = super()._get_demo_data_move()
+        data[f'{cid}_demo_invoice_5']['l10n_latam_document_number'] = '1-1'
+        data[f'{cid}_demo_invoice_equipment_purchase']['l10n_latam_document_number'] = '1-2'
+        return model, data

addons/l10n_ar/models/account_move.py

@@ -62,7 +62,6 @@ class AccountMove(models.Model):
         product_types = set([x.product_id.type for x in invoice_lines if x.product_id])
         consumable = set(['consu', 'product'])
         service = set(['service'])
-        mixed = set(['consu', 'service', 'product'])
         # on expo invoice you can mix services and products
         expo_invoice = self.l10n_latam_document_type_id.code in ['19', '20', '21']