fix: support windows via subprocess

[TendTo]

Proposed changes

Slight change in the subprocess invocation to support Windows.

Fixes

The subprocess command used to invoke mona would fail on Windows.

Types of changes

• Bugfix (non-breaking change which fixes an issue)

Checklist

• Lint and unit tests pass locally with my changes
  • Some tests failed, but I'm not sure if it depends on my changes. I would see what happens in the Github actions
• I have added tests that prove my fix is effective or that my feature works
  • Due to the miniscule nature of the changes, it should not be necessary