Resolve lutaml-model conflict warning

[ronaldtse]

     [Lutaml::Model] DEPRECATED: no_root is deprecated. Simply omit the element declaration for type-only models. Use type_name() to
     set the XSD type name.

     [Lutaml::Model] WARN:~/.local/share/mise/installs/ruby/3.4.8/lib/ruby/gems/3.4.0/gems/relaton-bib-2.1.2/lib/relaton/b
     ib/model/ext.rb:9:in '<class:Ext>' Attribute `doctype` overrides a method. Ensure you call `super` if needed, or consider
     renaming.