minor: Remove unused warnings

src/ldap/dn.rs

@@ -137,6 +137,7 @@ impl Dn {
     /// Overrides the DN hostname (`dc` fields) with the provided host.
     ///
     /// When no `dc` fields are present, they are only added when `force` is true.
+    #[expect(unused)]
     pub fn set_hostname(&mut self, host: &str, force: bool) {
         let domain_components: Vec<String> =
             host.split('.').map(|x| dn_escape(x).to_string()).collect();