Remove nektos, act files, and unused export path check utility (#6998)

# Pull Request

## 📖 Description

This change:
- Removes the nektos workflow checks in favor of using githubs CLI
- Removes an unused helper function now that `@microsoft/fast-components` and `@microsoft/fast-foundation` are both deprecated

## 👩‍💻 Reviewer Notes

This is just some cleanup work for unused files.

## ✅ Checklist

### General

<!--- Review the list and put an x in the boxes that apply. -->

- [ ] I have included a change request file using `$ yarn change`
- [ ] I have added tests for my changes.
- [x] I have tested my changes.
- [x] I have updated the project documentation to reflect my changes.
- [x] I have read the [CONTRIBUTING](https://github.com/microsoft/fast/blob/master/CONTRIBUTING.md) documentation and followed the [standards](https://github.com/microsoft/fast/blob/master/CODE_OF_CONDUCT.md#our-standards) for this project.

.github/workflows/README.md

@@ -0,0 +1,5 @@
+# Testing
+
+To test workflows, use the GitHub CLI and trigger the workflow from a branch.
+
+For more information see the [GitHub CLI documentation](https://cli.github.com/manual/gh_workflow_run).