Merge branch '337432-remove-only_opened-scope' into 'master'

Remove unused only_opened scope

See merge request gitlab-org/gitlab!73924

app/models/concerns/issuable.rb

@@ -92,7 +92,6 @@ module Issuable
     scope :recent, -> { reorder(id: :desc) }
     scope :of_projects, ->(ids) { where(project_id: ids) }
     scope :opened, -> { with_state(:opened) }
-    scope :only_opened, -> { with_state(:opened) }
     scope :closed, -> { with_state(:closed) }
 
     # rubocop:disable GitlabSecurity/SqlInjection