[FIX] website_sale: wait for the editor to be loaded

As the tour `shop_editor` is very small, it finishes before the editor
itself is fully loaded.

As a consequence, some threads are remaining on the server side and can
lead to a complete failure of the test.

This seems to particularly affects builds on Bookwork with werkzeug
2.2.2 and python 3.11 as it leads to werkzeug requests timeout.

With this commit, a step is added at the beginning of the test to ensure
that the editor is loaded before beginning the test by itself.

closes odoo/odoo#112698

Signed-off-by: William Braeckman (wbr) <wbr@odoo.com>
Signed-off-by: Christophe Monniez (moc) <moc@odoo.com>

addons/website_sale/static/tests/tours/website_sale_shop_editor_tour.js

@@ -6,6 +6,9 @@ registry.category("web_tour.tours").add('shop_editor', {
     test: true,
     url: '/shop?enable_editor=1',
     steps: [{
+    trigger: '#oe_snippets.o_loaded',
+    content: "Wait for the editor to be loaded"
+}, {
     content: "Click on pricelist dropdown",
     trigger: "iframe div.o_pricelist_dropdown a[data-bs-toggle=dropdown]",
 }, {