message: Unnecessary Box for kwargs
  Summary: `Box` is there for historical reasons? Not really needed.
diff: @@ -411,7 +411,7 @@ impl<'v, V: ValueLike<'v>> ParametersSpec<V> {
  /// Lazily initialized `kwargs` object.
  #[derive(Default)]
  struct LazyKwargs<'v> {
  - kwargs: Option<Box<SmallMap<StringValue<'v>, Value<'v>>>>,
  + kwargs: Option<SmallMap<StringValue<'v>, Value<'v>>>,
  }
  impl<'v> LazyKwargs<'v> {
  @@ -422,7 +422,7 @@ impl<'v, V: ValueLike<'v>> ParametersSpec<V> {
  None => {
  let mut mp = SmallMap::with_capacity_largest_vec();
  mp.insert_hashed(key, val);
  - self.kwargs = Some(box mp);
  + self.kwargs = Some(mp);
  false
  }
  Some(mp) => mp.insert_hashed(key, val).is_some(),
  @@ -431,7 +431,7 @@ impl<'v, V: ValueLike<'v>> ParametersSpec<V> {
  fn alloc(self, heap: &'v Heap) -> Value<'v> {
  let kwargs = match self.kwargs {
  - Some(kwargs) => Dict::new(coerce(*kwargs)),
  + Some(kwargs) => Dict::new(coerce(kwargs)),
  None => Dict::default(),
  };
  heap.alloc(kwargs)
  