message: Remove hash_layout
diff: @@ -147,11 +147,7 @@ mod paint {
  )
  }
  - fn hash_layout(&self, state: &mut Hasher) {
  - use std::hash::Hash;
  -
  - self.strokes.len().hash(state);
  - }
  + fn hash_layout(&self, _state: &mut Hasher) {}
  fn on_event(
  &mut self,
  