Complex Into<Callback> props broken with Leptos update

[MikeOnTea]

The upgrade from Leptos 0.8.12 to 0.8.14 broke more complex into props in components involving server functions. The error is:

multiple `impl`s satisfying `{closure@test_app.rs}: leptos::prelude::IntoReactiveValue<leptos::prelude::Callback<((),)>, _>` found in the `reactive_graph` crate:
            - impl<I, O, F> leptos::prelude::IntoReactiveValue<leptos::prelude::Callback<I, O>, leptos::prelude::__IntoReactiveValueMarkerCallbackSingleParam> for F
              where <F as std::ops::FnOnce<(I,)>>::Output == O, F: Fn(I), F: std::marker::Send, F: std::marker::Sync, F: 'static;
            - impl<T, I> leptos::prelude::IntoReactiveValue<T, leptos::reactive_graph::__IntoReactiveValueMarkerBaseCase> for I
              where I: std::convert::Into<T>;
note: required by a bound in `TestPropsBuilder::<T, (___pd, ())>::cb`

The most minimal example i managed to come up with is this:

#[component]
fn TestApp() -> impl IntoView {
	let (count, set_count) = signal(0);
	//works with explicit callback:
	//let cb = Callback::new(move |_| *set_count.write() += 1);
	let cb = move |_| *set_count.write() += 1;
	view! {
		<Test<TestFn> cb=cb/>
	}
}

#[server(TestFn)]
async fn test_fn() -> Result<(), ServerFnError> {
	Ok(())
}

#[component]
fn Test<T>(#[prop(optional)] _pd: PhantomData<T>, #[prop(into)] cb: Callback<(<T as ServerFn>::Output,)>) -> impl IntoView
where
	T: Sync + ServerFn<Protocol = Http<PostUrl, Json>> + 'static + Clone + for<'de> serde::Deserialize<'de>,
	<T as ServerFn>::Output: Sync + Clone,
	<T as ServerFn>::Error: Send + Sync + Clone + Display,
	<T as ServerFn>::Client: Client<<T as ServerFn>::Error>,
{
    //the real app of course invokes the callback, but i don't think this is relevant for the example
}

I was only able to reproduce this with such complex callbacks involving server functions, very simple Into Callbacks worked fine. Also, i don't think this is a big deal, in the few places this occurred in my app i just used an explicit Callback as a workaround, so it's probably not worth to invest too much time into this.