Merge branch 'group-new-miletone-breadcrumb' into 'master'

Fixed new group milestone breadcrumb

Closes #40338

See merge request gitlab-org/gitlab-ce!15511

app/views/groups/milestones/new.html.haml

 - breadcrumb_title "Milestones"
 - page_title "Milestones"
-- header_title group_title(@group, "Milestones", group_milestones_path(@group))
 
 %h3.page-title
   New Milestone

changelogs/unreleased/group-new-miletone-breadcrumb.yml

+---
+title: Fixed new group milestone breadcrumbs
+merge_request:
+author:
+type: fixed