[Python] Improve test coverage by deleting code that is not in use

Please find **one place** in the source code test coverage that is not in use and delete it.

To close the issue:
- [ ] remove one line that is not tested and not useful
- [ ] create a pull request with your changes and get it merged

What will help:

- Follow the documented [development setup](https://icalendar.readthedocs.io/en/latest/install.html#development-setup)
- After running the tests, you will have a coverage report as an HTML file.
- Talk to us if the line is really useless if you are in doubt.
- Create a Pull Request and we will see the improvements.

Thanks for your help to improve this project!

Follow the documented development setup, run the test suite, and inspect the generated HTML coverage report for an untested source line. Confirm with maintainers that the line is unused before removing it; done means one unnecessary line is deleted and the change is submitted in a pull request.

Written by the indexing model from the issue text.