Remove unused js class

This change removes the class `js-title-container` from the breadcrumbs.

This js-* class is not used except for a single quarantined test. This
change also updates the test when it is taken out of quarantine it
still passes.

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

@@ -9,7 +9,7 @@
       = button_tag class: 'toggle-mobile-nav', type: 'button' do
         %span.sr-only= _("Open sidebar")
         = sprite_icon('hamburger', size: 18)
-    .breadcrumbs-links.js-title-container{ data: { qa_selector: 'breadcrumb_links_content' } }
+    .breadcrumbs-links{ data: { testid: 'breadcrumb-links', qa_selector: 'breadcrumb_links_content' } }
       %ul.list-unstyled.breadcrumbs-list.js-breadcrumbs-list
         - unless hide_top_links
           = header_title

spec/features/projects/sub_group_issuables_spec.rb

@@ -16,18 +16,18 @@ RSpec.describe 'Subgroup Issuables', :js do
   it 'shows the full subgroup title when issues index page is empty' do
     visit project_issues_path(project)
 
-    expect_to_have_full_subgroup_title
+    expect_to_have_breadcrumb_links
   end
 
   it 'shows the full subgroup title when merge requests index page is empty' do
     visit project_merge_requests_path(project)
 
-    expect_to_have_full_subgroup_title
+    expect_to_have_breadcrumb_links
   end
 
-  def expect_to_have_full_subgroup_title
-    title = find('.breadcrumbs-links')
+  def expect_to_have_breadcrumb_links
+    links = find('[data-testid="breadcrumb-links"]')
 
-    expect(title).to have_content 'group subgroup project'
+    expect(links).to have_content 'group subgroup project'
   end
 end

spec/support/shared_examples/features/error_tracking_shared_example.rb

@@ -2,7 +2,7 @@
 
 RSpec.shared_examples 'error tracking index page' do
   it 'renders the error index page', quarantine: { issue: 'https://gitlab.com/gitlab-org/gitlab/-/issues/217810' } do
-    within('div.js-title-container') do
+    within('[data-testid="breadcrumb-links"]') do
       expect(page).to have_content(project.namespace.name)
       expect(page).to have_content(project.name)
     end