Fixed breadcrumb title not linking

This fixes the breadcrumb titles not having links. This was a regression
in the updated breadcrumbs introduced in 10.0.

This introduces the link for all pages rather than selectively doing it.
This will cover issues, merge requests, pipelines, jobs etc.

Closes #38059

app/helpers/breadcrumbs_helper.rb

@@ -10,11 +10,7 @@ module BreadcrumbsHelper
   def breadcrumb_title_link
     return @breadcrumb_link if @breadcrumb_link
 
-    if controller.available_action?(:index)
-      url_for(action: "index")
-    else
-      request.path
-    end
+    request.path
   end
 
   def breadcrumb_title(title)

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

@@ -16,5 +16,5 @@
             = breadcrumb_list_item link_to(extra[:text], extra[:link])
         = render "layouts/nav/breadcrumbs/collapsed_dropdown", location: :after
         %li
-          %h2.breadcrumbs-sub-title= @breadcrumb_title
+          %h2.breadcrumbs-sub-title= link_to @breadcrumb_title, breadcrumb_title_link
     = yield :header_content

changelogs/unreleased/breadcrumb-item-links.yml

+---
+title: Fixed issue/merge request breadcrumb titles not having links
+merge_request:
+author:
+type: fixed

spec/features/issues_spec.rb

@@ -131,6 +131,14 @@ describe 'Issues' do
   end
 
   describe 'Issue info' do
+    it 'links to current issue in breadcrubs' do
+      issue = create(:issue, project: project)
+
+      visit project_issue_path(project, issue)
+
+      expect(find('.breadcrumbs-sub-title a')[:href]).to end_with(issue_path(issue))
+    end
+
     it 'excludes award_emoji from comment count' do
       issue = create(:issue, author: user, assignees: [user], project: project, title: 'foobar')
       create(:award_emoji, awardable: issue)