Ignore buggy clippy::assigning_clones lint

```
error: assigning the result of `ToOwned::to_owned()` may be inefficient
   --> src/stl/mod.rs:613:9
    |
613 |         mesh.name = name.to_owned();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `clone_into()`: `name.clone_into(&mut mesh.name)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assigning_clones
    = note: `-D clippy::assigning-clones` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::assigning_clones)]`
```

src/stl/mod.rs

@@ -609,6 +609,7 @@ impl FromStl for Mesh {
         mesh.faces.push(vertices_indices);
     }
 
+    #[allow(clippy::assigning_clones)] // https://github.com/rust-lang/rust-clippy/issues/12502
     fn set_name(mesh: &mut Self::Context, name: &str) {
         mesh.name = name.to_owned();
     }