Add compat downgrade YAML

[xlxs4]

Checklist

• [ ] Appropriate tests were added
• [ ] Any code changes were done in a way that does not break public API
• [ ] All documentation related to code changes were updated
• [ ] The new code follows the contributor guidelines, in particular the ScioML Style Guide and COLPRAC.
• [ ] Any new documentation only uses public API

Additional context

Ref. https://github.com/SciML/SciMLBase.jl/pull/553