Remove unnecessary clippy allow

src/to_artifact.rs

@@ -17,8 +17,6 @@ macro_rules! to_artifact {
 for_each_tuple!(to_artifact);
 
 impl<T: Resource> ToArtifact for Option<T> {
-  // FIXME: https://github.com/rust-lang/rust-clippy/issues/2843
-  #![allow(clippy::use_self)]
   type Artifact = Option<T::Artifact>;
 }