Migrate "app/assets/javascripts/projects/settings_service_desk/components/service_desk_template_dropdown.vue" to GlDisclosureDropdown or GlCollapsibleListbox

One or more dropdowns in app/assets/javascripts/projects/settings_service_desk/components/service_desk_template_dropdown.vue should be migrated to one of the new dropdown components. See the parent epic for guidance on migration strategies.