[FIX] website_sale_slides: fix name of products of the type 'course' in SOL

Currently, the name of products of the type 'course' in SOL was missing
due to the split by '\n' in name_get.

So this commit fixes this issue and remove the \n  if there is
only one payment channel for course.

task-2823432

closes odoo/odoo#93836

X-original-commit: 289c3219b7975ebee8748223a136e1d752da440f
Related: odoo/enterprise#28499
Signed-off-by: Laurent Stukkens (ltu) <ltu@odoo.com>

addons/website_sale_slides/models/product_product.py

@@ -15,4 +15,5 @@ class Product(models.Model):
         if not payment_channels:
             return super(Product, self).get_product_multiline_description_sale()
 
-        return _('Access to:\n%s', '\n'.join(payment_channels.mapped('name')))
+        new_line = '' if len(payment_channels) == 1 else '\n'
+        return _('Access to:%s%s', new_line, '\n'.join(payment_channels.mapped('name')))