Remove explicit default constructor for Accessor

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

tiny_gltf.h

@@ -898,7 +898,6 @@ struct Accessor {
     // unreachable return 0;
   }
 
-  Accessor() = default;
   DEFAULT_METHODS(Accessor)
   bool operator==(const tinygltf::Accessor &) const;
 };