[REF] website_*: Change registerTours of tour_utils

As steps are encapsuled in an arrow function from
69a5d8e3ce47238 for steps tour definition to avoid
direct Markup(_t()) interpretation, the same is done
for registerWebsitePreviewTour() of
"odoo/addons/website/static/src/js/tours/tour_utils.js"
in this commit.

This is done in anticipation of the use of
_t() (import from @web/core/l10n/translation) with
registerWebsitePreviewTour().

task-3292454

closes odoo/design-themes#678

Related: odoo/odoo#130248
Signed-off-by: Luca Vitali (luvi) <luvi@odoo.com>

theme_test_custo/static/tests/tours/theme_menu_hierarchies.js

@@ -5,7 +5,7 @@ import wTourUtils from '@website/js/tours/tour_utils';
 wTourUtils.registerWebsitePreviewTour('theme_menu_hierarchies', {
     url: '/example',
     test: true,
-}, [
+}, () => [
     {
         content: 'Check Mega Menu is correctly created',
         trigger: 'iframe #top_menu a.o_mega_menu_toggle',