Remove the vscode-syntax-highlighting package (#6964)

# Pull Request

## 📖 Description

Removal of the `fast-tagged-templates` package as this is being deprecated.

### 🎫 Issues

Closes #6953.

## ✅ 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.
- [ ] 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](/docs/community/code-of-conduct/#our-standards) for this project.

## ⏭ Next Steps

- Post a deprecated message to the npm package.

Author: janechu

.prettierignore

@@ -9,4 +9,3 @@
 **/dist
 **/temp
 default-palette.ts
-packages/tooling/fast-vscode-syntax-highlighting/test