Replace `data-confirm` modals with `GlModal` in group hooks

ee/app/views/groups/hooks/edit.html.haml

@@ -13,4 +13,4 @@
 
       %span>= f.submit _('Save changes'), class: 'gl-button btn btn-confirm gl-mr-3'
       = render 'shared/web_hooks/test_button', hook: @hook
-      = link_to _('Delete'), group_hook_path(@group, @hook), method: :delete, class: 'gl-button btn btn-danger float-right', data: { confirm: _('Are you sure?') }
+      = link_to _('Delete'), group_hook_path(@group, @hook), method: :delete, class: 'gl-button btn btn-danger float-right', aria: { label: s_('Webhooks|Delete webhook') }, data: { confirm: s_('Webhooks|Are you sure you want to delete this group hook?'), confirm_btn_variant: 'danger' }

locale/gitlab.pot

@@ -40704,6 +40704,9 @@ msgstr ""
 msgid "Webhooks|An issue is created, updated, closed, or reopened."
 msgstr ""
 
+msgid "Webhooks|Are you sure you want to delete this group hook?"
+msgstr ""
+
 msgid "Webhooks|Are you sure you want to delete this project hook?"
 msgstr ""