Avoid clippy::let-underscore-drop

The following main.rs replicates the clippy warning:

```
use yew::prelude::*;

struct Props {
    droppable: Vec<()>,
}

fn component(props: &Props) -> Html {
    let props = Props { droppable: Vec::new() };
    html! { <Component ..props /> }
}

fn main() {}
```

If I'm not mistaken this happens when using the `..` on any `Properties` with a field that implements `Drop`.

packages/yew-macro/src/props/component.rs

@@ -64,7 +64,7 @@ impl ComponentProps {
             .iter()
             .map(|Prop { label, .. }| {
                 quote_spanned! {Span::call_site().located_at(label.span())=>
-                    let _ = #props_ident.#label;
+                    let _ = &#props_ident.#label;
                 }
             })
             .collect();