[FIX] base: force compute active_lang_count

Create a new contact (just open the create form)

The "Language" field is missing, because active_lang_count is not
computed before the record is saved, but it is necessary to display the
language field

opw-2149324

closes odoo/odoo#41162

Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

odoo/addons/base/models/res_partner.py

@@ -234,6 +234,7 @@ class Partner(models.Model):
         for partner in self:
             partner.display_name = names.get(partner.id)
 
+    @api.depends('lang')
     def _compute_active_lang_count(self):
         lang_count = len(self.env['res.lang'].get_installed())
         for partner in self: