Fixes PopupService scopes problem

[bdovaz]

Description of Change

Corrects the regression added in 9.1.1 with the IDispatcher dependency.

Linked Issues

• Fixes #2332

  PR Checklist

• [x] Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• [ ] Has tests (if omitted, state reason in description)
• [ ] Has samples (if omitted, state reason in description)
• [x] Rebased on top of main at time of PR
• [x] Changes adhere to coding standard

• [ ] Documentation created or updated: https://github.com/MicrosoftDocs/CommunityToolkit/pulls

  Additional information

[brminnick]

Thanks @bdovaz!