crown: Do not check trait item projections. (#36095)

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

components/script/dom/webgpu/wgsllanguagefeatures.rs

@@ -54,8 +54,6 @@ impl WGSLLanguageFeaturesMethods<crate::DomTypeHolder> for WGSLLanguageFeatures
     }
 }
 
-// this error is wrong because if we inline Self::Key and Self::Value all errors are gone
-#[cfg_attr(crown, allow(crown::unrooted_must_root))]
 impl Setlike for WGSLLanguageFeatures {
     type Key = DOMString;