Make Routable derive macro hygienic (#3437)

packages/router-macro/src/lib.rs

@@ -257,6 +257,7 @@ pub fn routable(input: TokenStream) -> TokenStream {
     let routable_impl = route_enum.routable_impl();
 
     (quote! {
+        const _: () = {
             #error_type
 
             #display_impl
@@ -264,6 +265,7 @@ pub fn routable(input: TokenStream) -> TokenStream {
             #routable_impl
 
             #parse_impl
+        };
     })
     .into()
 }