Merge branch 'jivanvl-replace-append-bottom-20-admin-runners' into 'master'

Replace append-bottom-20 in admin/runners

See merge request gitlab-org/gitlab!38728

app/views/admin/runners/show.html.haml

@@ -28,7 +28,7 @@
     %p You can't make this a shared Runner.
 %hr
 
-.append-bottom-20
+.gl-mb-6
   = render 'shared/runners/form', runner: @runner, runner_form_url: admin_runner_path(@runner), in_gitlab_com_admin_context: Gitlab.com?
 
 .row