message: Fix clippy lint about unnecessary unit return type
diff: @@ -270,7 +270,7 @@ impl<REv> EffectBuilder<REv> {
  /// Can be used to trigger events from effects when combined with `.event`. Do not use this do
  /// "do nothing", as it will still cause a task to be spawned.
  #[inline(always)]
  - pub async fn immediately(self) -> () {}
  + pub async fn immediately(self) {}
  /// Sets a timeout.
  pub(crate) async fn set_timeout(self, timeout: Duration) -> Duration {
  