Make some buttons green again

Fix missing .btn-success class on the following buttons:
* 'Create milestone' button
* Secondary button on profile tabs

`btn-create` was an old class which was was removed in !23232
and replaced with `btn-success`,
but these two seem to have been missed in the process.

app/views/shared/empty_states/_profile_tabs.html.haml

@@ -12,7 +12,7 @@
           %p= current_user_empty_message_description
 
         - if secondary_button_link.present?
-          = link_to secondary_button_label, secondary_button_link, class: 'btn btn-create btn-inverted'
+          = link_to secondary_button_label, secondary_button_link, class: 'btn btn-success btn-inverted'
 
         = link_to primary_button_label, primary_button_link, class: 'btn btn-success'
       - else

changelogs/unreleased/fix-create-milestone-btn-success.yml

+---
+title: Fix style of secondary profile tab buttons.
+merge_request: 32010
+author: Wolfgang Faust
+type: fixed