Updated UTR docker.ts paths to Windows

[asyasmi]

Changed paths to Windows workspace path.

Changes

• Updated Windows path for workspace, according to the similar path in https://github.com/game-ci/unity-builder/blob/main/src/model/docker.ts#L78

Checklist

• [x] Read the contribution guide and accept the code of conduct
• [x] Readme (updated or not needed)
• [x] Tests (added, updated or not needed)

[github-actions[bot]]

[AndrewKahr]

This PR has been superseded by the PR I merged. However, I've made sure to credit your contribution in the release notes. Thanks for the fix!