Fix broken button detault class

app/views/shared/notifications/_button.html.haml

@@ -17,7 +17,7 @@
       .js-notification-toggle-btns
         %div{ class: ("btn-group" if notification_setting.custom?) }
           - if notification_setting.custom?
-            %button.dropdown-new.btn.btn-defaul.btn-icon.gl-button.has-tooltip.notifications-btn.text-left#notifications-button{ type: "button", title: button_title, class: "#{btn_class}", "aria-label" => aria_label, data: { container: "body", toggle: "modal", target: "#" + notifications_menu_identifier("modal", notification_setting), display: 'static' } }
+            %button.dropdown-new.btn.btn-default.btn-icon.gl-button.has-tooltip.notifications-btn.text-left#notifications-button{ type: "button", title: button_title, class: "#{btn_class}", "aria-label" => aria_label, data: { container: "body", toggle: "modal", target: "#" + notifications_menu_identifier("modal", notification_setting), display: 'static' } }
               = sprite_icon("notifications", css_class: "js-notification-loading")
               = notification_title(notification_setting.level)
             %button.btn.dropdown-toggle.d-flex{ data: { toggle: "dropdown", target: notifications_menu_identifier("dropdown", notification_setting), flip: "false" } }

changelogs/unreleased/notificaion-button-class.yml

+---
+title: Fix broken button default class
+merge_request: 43977
+author:
+type: fixed