Use #![register_tool] instead of #![register_attr]

CC https://github.com/rust-lang/rust/issues/66079

components/script/dom/bindings/reflector.rs

@@ -30,7 +30,7 @@ where
 /// A struct to store a reference to the reflector of a DOM object.
 #[allow(unrooted_must_root)]
 #[derive(MallocSizeOf)]
-#[must_root]
+#[unrooted_must_root_lint::must_root]
 // If you're renaming or moving this field, update the path in plugins::reflector as well
 pub struct Reflector {
     #[ignore_malloc_size_of = "defined and measured in rust-mozjs"]