Bump @tootallnate/once and @vscode/test-electron

Removes [@tootallnate/once](https://github.com/TooTallNate/once). It's no longer used after updating ancestor dependency [@vscode/test-electron](https://github.com/Microsoft/vscode-test). These dependencies need to be updated together.


Removes `@tootallnate/once`

Updates `@vscode/test-electron` from 1.6.2 to 2.5.2
- [Changelog](https://github.com/microsoft/vscode-test/blob/main/CHANGELOG.md)
- [Commits](microsoft/vscode-test@v1.6.2...v2.5.2)

---
updated-dependencies:
- dependency-name: "@tootallnate/once"
  dependency-version: 
  dependency-type: indirect
- dependency-name: "@vscode/test-electron"
  dependency-version: 2.5.2
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]