Fixes inconsistency in new builder API

[skrawcz]

The default should be a dictionary adapter. In the case that you were not using the "V2" functionality there was a typo and it would not set the adapter to the dictionary one, instead passing in None, and therefore defaulting to the dataframe adapter.

Changes

• driver.py
• test_hamilton_driver.py

How I tested this

• locally ran unit tests

Notes

• AFAICT nothing assumed this bug as a feature.

Checklist

• PR has an informative and human-readable title (this will be pulled into the release notes)
• Changes are limited to a single goal (no scope creep)
• Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future TODOs are captured in comments
• Project documentation has been updated if adding/changing functionality.

[elijahbenizzy]

LGTM