message: subscriber: fix clippy unused lifetime lint
  Okay, this is REALLY the last clippy lint this time.
diff: @@ -1396,7 +1396,7 @@ struct FmtLevel<F: ?Sized> {
  _f: PhantomData<fn(F)>,
  }
  -impl<'a, F: LevelNames> fmt::Display for FmtLevel<F> {
  +impl<F: LevelNames> fmt::Display for FmtLevel<F> {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  #[cfg(feature = "ansi")]
  {
  