[FIX] website_event_track: Properly sort tracks on website with P3

On Python 3, dict.keys() doesn't return a list, so we can't sort it, but
converting to a list on the fly before calling to sort() is not going to
change the original dict_keys object. Storing directly the list in the
variable, we get the expected result.

Side note: the daylist2 variable is there just for the t-set and was
already present in the code. Renaming it to dummy would be clearer
but that should not be done in stable.

Closes #25113.

addons/website_event_track/views/event_track_templates.xml

@@ -50,8 +50,8 @@
                 <input type="text" class="form-control" placeholder="Filter Tracks..." id="event_track_search"/>
             </div>
         </section>
-        <t t-set="dayslist" t-value="days.keys()"/>
-        <t t-set="dayslist2" t-value="list(dayslist).sort()"/> <!-- display days in the right order -->
+        <t t-set="dayslist" t-value="list(days.keys())"/>
+        <t t-set="dayslist2" t-value="dayslist.sort()"/> <!-- display days in the right order -->
         <section class="container" t-foreach="dayslist" t-as="day">
             <t t-set="locations" t-value="days[day]['locations']"/>
             <t t-set="dates" t-value="days[day]['dates']"/>