Ignore a clippy warning

Summary: Warning enabled in the most recent Clippy that comes out as an error. Need to disable it so we make the Starlark CI work.

Reviewed By: JakobDegen

Differential Revision: D47226540

fbshipit-source-id: 3d81b2b81d360a5027dedf09035151e4a6818924

Author: ndmitchell

gazebo/dupe_derive/src/clone.rs

@@ -20,6 +20,10 @@ pub fn derive_clone_(input: proc_macro::TokenStream) -> proc_macro::TokenStream
     let name = &input.ident;
     let body = duplicate_impl(&input.data, &quote! { ::std::clone::Clone::clone });
     let gen = quote! {
+        // Clippy wants us to use Copy if we can - we prefer to be agnostic.
+        // Add unknown_lints temporarily.
+        #[allow(unknown_lints)]
+        #[allow(clippy::incorrect_clone_impl_on_copy_type)]
         impl #impl_generics ::std::clone::Clone for #name #ty_generics #where_clause {
             fn clone(&self) -> Self {
                 #body