Python CLI Publication: Provide Nightly Build

### Is your feature request related to a problem? Please describe.

We could provide nightly builds to provide convenient access to the latest main version of the Python CLI for dev purposes only. The nightly build will be published to https://test.pypi.org/ instead. Developers could try and test it via
```
pip install -i https://test.pypi.org/simple/ --pre
```

This could help us verify the CLI for dev purpose easily.

### Describe the solution you'd like

_No response_

### Describe alternatives you've considered

_No response_

### Additional context

_No response_

Start with the Python CLI package and the test.pypi.org installation command shown in the issue. Locate the repository's existing build and publication entry points, then determine how a nightly artifact can be published to TestPyPI. Done means developers can install the latest main build with the documented pip command.

Written by the indexing model from the issue text.