[FIX] website_event: make Attendee # translatable

On the website,
when registering for an event with ticket,
the placeholder `Attendee #` could not be translated,
as `t-att` attributes are not translated.

An alternative is to put the string to translate
in a `t-set` node, which can be translated, and
to use the variable assigned in this `t-set`
in the `t-att` attribute.

opw-678758

addons/website_event/i18n/website_event.pot

@@ -117,6 +117,11 @@ msgstr ""
 msgid "All Events"
 msgstr ""
 
+#. module: website_event
+#: model:ir.ui.view,arch_db:website_event.registration_attendee_details
+msgid "Attendee #%s"
+msgstr ""
+
 #. module: website_event
 #: model:ir.ui.view,arch_db:website_event.registration_attendee_details
 msgid "Cancel Registration"

addons/website_event/views/website_event.xml

@@ -465,7 +465,8 @@
                                 <t t-foreach="range(1, ticket['quantity'] + 1)" t-as="att_counter" name="attendee_loop">
                                     <t t-set="counter" t-value="counter + 1"/>
                                     <div class="row mb4">
-                                        <div class="col-md-4"><input class='form-control' type='text' t-attf-name="#{counter}-name" required="This field is required" t-att-placeholder="'Attendee #%s' %counter"/></div>
+                                        <t t-set="attendee_placeholder">Attendee #%s</t>
+                                        <div class="col-md-4"><input class='form-control' type='text' t-attf-name="#{counter}-name" required="This field is required" t-att-placeholder="attendee_placeholder %counter"/></div>
                                         <div class="col-md-5"><input class='form-control' type='email' t-attf-name="#{counter}-email" required="This field is required"/></div>
                                         <div class="col-md-3"><input class='form-control' type='tel' t-attf-name="#{counter}-phone"/></div>
                                         <input class='hidden' type='text' t-attf-name="#{counter}-ticket_id" t-attf-value="#{ticket['id']}"/>