fix: remove optimist dep

[chohmann]

Motivation and Context

#11028

Description

Need to remove optimist dep from this package, then use this package in http-spec, then use that upgraded http-spec version in prism.

How Has This Been Tested?

1. pull branch locally
2. run the cli with node ./bin/cli and whatever options you want to pass in
3. ensure they cli options work as expected

Screenshot(s)/recordings(s)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• This PR's code follows as closely as possible the coding style/guidelines of this project.
• I have added error reporting and followed the error reporting guidelines.
• I have added event tracking and followed the event tracking guidelines.
• I have updated any relevant documentation accordingly to reflect this PR's changes.
• I have added automated tests (unit/integration/e2e/other) to cover my changes.
• All new and existing tests pass locally (excluding flaky CI tests).

[stoplight-bot]

🎉 This PR is included in version 1.0.1 🎉

The release is available on:

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

Your semantic-release bot 📦🚀