use BumpBox<Any> and FromAnyValue instead of sync bounds

packages/core/tests/kitchen_sink.rs

@@ -36,7 +36,7 @@ fn dual_stream() {
             LoadTemplate { name: "template", index: 0, id: ElementId(1) },
             SetAttribute {
                 name: "class",
-                value: "123".into_value(&bump),
+                value: (&*bump.alloc("123".into_value(&bump))).into(),
                 id: ElementId(1),
                 ns: None,
             },