Remove unused partial remove_approver

This partial is not used anywhere in the codebase:
- UI is dated (added 4 years ago) and not polished,
like work in progress.
- Includes placeholder text and links and no JS to back
up logic.
- There is another approvers feature available.

Changelog: removed

app/views/shared/issuable/_form.html.haml

@@ -75,8 +75,6 @@
     - if can?(current_user, :"destroy_#{issuable.to_ability_name}", @project)
       = link_to 'Delete', polymorphic_path([@project, issuable], params: { destroy_confirm: true }), data: { confirm: _('%{issuableType} will be removed! Are you sure?') % { issuableType: issuable.human_class_name } }, method: :delete, class: 'btn gl-button btn-danger btn-danger-secondary gl-float-right'
 
-= render_if_exists 'shared/issuable/remove_approver'
-
 - if issuable.respond_to?(:issue_type)
   = form.hidden_field :issue_type
 

ee/app/views/shared/issuable/_remove_approver.html.haml

-%li.unsaved-approvers.hide.approver.approver-template{ id: "user_{user_id}" }
-  = link_to "{approver_name}", "#"
-  .float-right
-    = link_to "#", data: { confirm: "Are you sure you want to remove approver {approver_name}"}, class: "btn-sm btn btn-danger gl-button", title: _('Remove approver') do
-      = sprite_icon("close", css_class: "gl-icon")
-      = _("Remove")

locale/gitlab.pot

@@ -30058,9 +30058,6 @@ msgstr ""
 msgid "Remove all or specific reviewer(s)"
 msgstr ""
 
-msgid "Remove approver"
-msgstr ""
-
 msgid "Remove approvers"
 msgstr ""