Compilation fix: Use as_str rather than as_ref

[hovinen]

Previously, we got the following compilation error with rustc 1.99 and Blitz HEAD:

 1  error[E0283]: type annotations needed
    --> /home/hovinen/dev/dioxus/dioxus/packages/native-dom/src/mutation_writer.rs:435:35
     |
 435 |             if element_name.local.as_ref() == "object" {
     |                                   ^^^^^^
     |
     = note: multiple `impl`s satisfying `string_cache::atom::Atom<web_atoms::LocalNameStaticSet>: AsRef<_>` found in the `string_cache` crate:
             - impl<Static> AsRef<[u8]> for string_cache::atom::Atom<Static>
               where Static: string_cache::static_sets::StaticAtomSet;
             - impl<Static> AsRef<str> for string_cache::atom::Atom<Static>
               where Static: string_cache::static_sets::StaticAtomSet;
 help: try using a fully qualified path to specify the expected types
     |
 435 -             if element_name.local.as_ref() == "object" {
 435 +             if <string_cache::atom::Atom<web_atoms::LocalNameStaticSet> as AsRef<T>>::as_ref(&element_name.local) == "object" {
     |

 For more information about this error, try `rustc --explain E0283`.
 error: could not compile `dioxus-native-dom` (lib) due to 1 previous error