Fix bug where Pester fails to run but workflow pipeline itself doesn't fail

[james-garriss]

🗣 Description

💭 Motivation and context

Created function to call Pester and check results to verify that it actually ran. Created Pester tests for the function and called the function in various places.

🧪 Testing

Closes: #1454

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• PR targets the correct parent branch (e.g., main or release-name) for merge.
• Changes are limited to a single goal - eschew scope creep!
• Changes are sized such that they do not touch excessive number of files.

I had to change some files related to PR 1450 b/c these changes were messing with that workflow. Rebase and merge will harmonize everything.

• These code changes follow the ScubaGear [content style guide]
• Related issues these changes resolve are linked preferably via [closing keywords]
• All relevant type-of-change labels added.
• All relevant project fields are set.
• All relevant repo and/or project documentation updated to reflect these changes.
• Unit tests added/updated to cover PowerShell and Rego changes.
• All relevant functional tests passed.
• All automated checks (e.g., linting, static analysis, unit/smoke tests) passed.

✅ Pre-merge checklist

• PR passed smoke test check.
• Feature branch has been rebased against changes from parent branch, as needed
• Resolved all merge conflicts on branch
• Notified merge coordinator that PR is ready for merge via comment mention
• Demonstrate changes to the team for questions and comments.

✅ Post-merge checklist

• Feature branch deleted after merge to clean up repository.
• Verified that all checks pass on parent branch (e.g., main or release-name) after merge.