Warn when unused keys are present in the config

Description

Warn when unused keys are present in the config

How Has This Been Tested?

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds or improves functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation improvement (updates to user guides, docstrings, or developer docs)

Checklist:

• [ ] My code follows the code style of this project and has been formatted using black.
• [ ] All new and existing tests passed, including on GPU (if relevant).
• [ ] I have added tests that cover my changes (if relevant).
• [ ] The option documentation (docs/options) has been updated with new or changed options.
• [ ] I have updated CHANGELOG.md.
• [ ] I have updated the documentation (if relevant).