Bump vscode-test from 1.4.1 to 1.5.1

Bumps [vscode-test](https://github.com/Microsoft/vscode-test) from 1.4.1 to 1.5.1.
- [Release notes](https://github.com/Microsoft/vscode-test/releases)
- [Changelog](https://github.com/microsoft/vscode-test/blob/master/CHANGELOG.md)
- [Commits](microsoft/vscode-test@1.4.1...v1.5.1)

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

Author: dependabot-preview[bot]