feat: support ipywidgets>8 by passing tuples to dropdown instead of dict

[devstein]

Description

Closes #769
Relates to jupyter-widgets/ipywidgets#2679

ipywidgets dropped supported for map types in 8.0.0 because drop downs should be ordered. This PR passes an ordered list of tuples to all of the references to Dropdown instead of a dict.

Note: dict support was re-added in jupyter-widgets/ipywidgets#3557, but still think it makes sense to move to an ordered list of tuples

Checklist

• Wrote a description of my changes above
• Formatted my code with black
• Added a bullet point for my changes to the top of the CHANGELOG.md file
• Added or modified unit tests to reflect my changes
• Manually tested with a notebook
• If adding a feature, there is an example notebook and/or documentation in the README.md file

[jasongrout]

FYI, ipywidgets 8.0.2 adds back in support for dicts since now dicts are ordered, though it isn't advertised in the docs: jupyter-widgets/ipywidgets#3557

[jasongrout]

FYI, ipywidgets 8.0.2 adds back in support for dicts since now dicts are ordered, though it isn't advertised in the docs: jupyter-widgets/ipywidgets#3557

This is noted in #769 (comment) too.

However, I think these changes look good to me, and an improvement.

[jasongrout]

LGTM

[devstein]

Thanks for reviewing @jasongrout! I saw that dict support was re-added, but thought the ordered list of tuples is clearer, so made the change.