[MIG] l10n_be: Migrate l10n_be_demo.yml in new API

addons/l10n_be/demo/l10n_be_demo.yml

 -
   Set the demo tags on account templates and on their respective accounts (already generated during the loading of data)
 -
-  !python {model: account.account.template} : |
+  !python {model: account.account.template, id: False}: |
       mapping_list = [
           ('a1000', 'account.demo_capital_account'),
           ('a300', 'account.demo_stock_account'),
@@ -10,9 +10,9 @@
           ('a24011', 'account.demo_coffee_machine_account'),
       ]
       for xml_id, tag in mapping_list:
-          account_template = self.browse(cr, uid, ref(xml_id))
-          self.write(cr, uid, account_template.id, {'tag_ids': [(4, ref(tag))]})
-          account_ids = self.pool.get('account.account').search(cr, uid, [('code', 'like', account_template.code)])
-          if account_ids:
-              self.pool.get('account.account').write(cr, uid, account_ids, {'tag_ids': [(4,ref(tag))]})
+          account_template = self.browse(ref(xml_id))
+          account_template.write({'tag_ids': [(4, ref(tag))]})
+          accounts = self.env['account.account'].search([('code', 'like', account_template.code)])
+          if accounts:
+              accounts.write({'tag_ids': [(4,ref(tag))]})