Make use_future take an impl FnMut + 'static, don't include router prelude when we don't need to

packages/router/tests/via_ssr/link.rs

@@ -1,5 +1,4 @@
 use dioxus::prelude::*;
-use dioxus_router::prelude::*;
 use std::str::FromStr;
 
 fn prepare<R: Routable>() -> String