Fixes CA policy deployment errors for workload identities

[AlfredSchreuder]

Pull Request (PR) description

Fixed CA policy deployment error for workload identities when there are just service principles included (or excluded) without users or applications.

Task list

• Added an entry to the change log under the Unreleased section of the file CHANGELOG.md.
  Entry should say what was changed and how that affects users (if applicable), and
  reference the issue being resolved (if applicable).
• Resource parameter descriptions added/updated in the schema.mof.
• Resource documentation added/updated in README.md.
• Resource settings.json file contains all required permissions.
• Examples appropriately added/updated.
• Unit tests added/updated.
• New/changed code adheres to DSC Community Style Guidelines.

[ykuijs]

LGTM