refactor(definition-list): convert tests to RTL - FE-6806

[DipperTheDan]

Proposed behaviour

Unit tests should use RTL

Current behaviour

Use tests use Enzyme

Checklist

• [x] Commits follow our style guide
• [ ] Related issues linked in commit messages if required
• [ ] Screenshots are included in the PR if useful
• [ ] All themes are supported if required
• [x] Unit tests added or updated if required
• [ ] Playwright automation tests added or updated if required
• [ ] Storybook added or updated if required
• [ ] Translations added or updated (including creating or amending translation keys table in storybook) if required
• [ ] Typescript d.ts file added or updated if required
• [ ] Related docs have been updated if required

QA

• [ ] Tested in provided StackBlitz sandbox/Storybook
• [ ] Add new Playwright test coverage if required
• [ ] Carbon implementation matches Design System/designs
• [ ] UI Tests GitHub check reviewed if required

Additional context

N/A

Testing instructions

N/A

[carbonci]

:tada: This PR is included in version 142.13.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: