fix: set shell to False if running subprocess on Windows

[my1e5]

Description

When running a subprocess through run in cmd.py, if the OS is Windows set shell=False.

Closes https://github.com/commitizen-tools/commitizen/issues/1118 and https://github.com/commitizen-tools/commitizen/issues/1117

Checklist

• [ ] Add test cases to all the changes you introduce
• [x] Run ./scripts/format and ./scripts/test locally to ensure this change passes linter check and test
• [x] Test the changes on the local machine manually
• [ ] Update the documentation for the changes

Expected behavior

Running rye run cz bump on a Windows machine in a rye-managed project now works.