BED-4363 - Refactor: Remove in-app migration sync for pure stepwise migrations

[mistahj67]

CLOSES BED-4363

Description

Just small cleanup noticed while working on BED-4363

Motivation and Context

This PR addresses: BED-4363

Why is this change required? What problem does it solve?
Better delineation between CE and BHE

How Has This Been Tested?

Locally ran both and ensured no issues

Types of changes

• Chore (a change that does not modify the application functionality)

Checklist:

• I have met the contributing prerequisites
  • Assigned myself to this PR
  • Added the appropriate labels
  • Associated an issue: Issues and Pull Requests README #672
  • Read the Contributing guide: https://github.com/SpecterOps/BloodHound/wiki/Contributing
• I have ensured that related documentation is up-to-date
  • Open API docs
  • Code comments (GoDocs / JSDocs)
• I have followed proper test practices
  • Added/updated tests to cover my changes
  • All new and existing tests passed