[FIX] calendar: test calendar month view start hour displayed

The `test_calendar_month_view_start_hour_displayed` makes sure
that start hour is display in calendar month view.

The test was failing because when clicking on scale selector,
it used '.dropdown-toggle:contains("Week")' however it might
happen that the current scale is not week.

This commit fixes this issue by changing the way we access
the scale selector.

fixes runbot-59023

closes odoo/odoo#156121

Signed-off-by: Arnaud Joset (arj) <arj@odoo.com>

addons/calendar/static/tests/tours/calendar_tour.js

@@ -48,7 +48,7 @@ registry.category("web_tour.tours").add("calendar_appointments_hour_tour", {
             run: "click",
         },
         {
-            trigger: '.dropdown-toggle:contains("Week")',
+            trigger: '.scale_button_selection',
             content: "Click to change calendar view",
             run: "click",
         },