Update markup for proper tracking

- Remove unused track_value

app/views/layouts/nav/_dashboard.html.haml

@@ -2,7 +2,7 @@
 -# https://gitlab.com/gitlab-org/gitlab-foss/issues/49713 for more information.
 %ul.list-unstyled.navbar-sub-nav
   - if dashboard_nav_link?(:projects)
-    = nav_link(path: ['root#index', 'projects#trending', 'projects#starred', 'dashboard/projects#index'], html_options: { id: 'nav-projects-dropdown', class: "home dropdown header-projects qa-projects-dropdown", data: { track_label: "projects_dropdown", track_event: "click_dropdown", track_value: "" } }) do
+    = nav_link(path: ['root#index', 'projects#trending', 'projects#starred', 'dashboard/projects#index'], html_options: { id: 'nav-projects-dropdown', class: "home dropdown header-projects qa-projects-dropdown", data: { track_label: "projects_dropdown", track_event: "click_dropdown" } }) do
       %button{ type: 'button', data: { toggle: "dropdown" } }
         = _('Projects')
         = sprite_icon('chevron-down', css_class: 'caret-down')
@@ -10,7 +10,7 @@
         = render "layouts/nav/projects_dropdown/show"
 
   - if dashboard_nav_link?(:groups)
-    = nav_link(controller: ['dashboard/groups', 'explore/groups'], html_options: { id: 'nav-groups-dropdown', class: "d-none d-md-block home dropdown header-groups qa-groups-dropdown", data: { track_label: "groups_dropdown", track_event: "click_dropdown", track_value: "" } }) do
+    = nav_link(controller: ['dashboard/groups', 'explore/groups'], html_options: { id: 'nav-groups-dropdown', class: "d-none d-md-block home dropdown header-groups qa-groups-dropdown", data: { track_label: "groups_dropdown", track_event: "click_dropdown" } }) do
       %button{ type: 'button', data: { toggle: "dropdown" } }
         = _('Groups')
         = sprite_icon('chevron-down', css_class: 'caret-down')
@@ -18,7 +18,7 @@
         = render "layouts/nav/groups_dropdown/show"
 
   - if any_dashboard_nav_link?([:groups, :milestones, :activity, :snippets])
-    %li.header-more.dropdown{ **tracking_attrs('main_navigation', 'click_more_link', 'navigation') }
+    = nav_link(html_options: { id: 'nav-more-dropdown', class: "header-more dropdown", data: { track_label: "more_dropdown", track_event: "click_more_link" } }) do
       %a{ href: "#", data: { toggle: "dropdown", qa_selector: 'more_dropdown' } }
         = _('More')
         = sprite_icon('chevron-down', css_class: 'caret-down')