message: Fix import of `Debug` in announcements module
diff: use std::{
  cell::RefCell,
  - fmt::{self, Display, Formatter},
  + fmt::{self, Debug, Display, Formatter},
  };
  use itertools::Itertools;
  @@ -55,7 +55,7 @@ pub(crate) enum ControlAnnouncement {
  },
  }
  -impl std::fmt::Debug for ControlAnnouncement {
  +impl Debug for ControlAnnouncement {
  fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
  match self {
  Self::FatalError { file, line, msg } => f
  