Is your feature request related to a problem? Please describe.
Types become a bit simpler to use from Python 3.10 up due to the pipe "|" operator. To simplify adding of type hints and demonstrate that this is a modern tool, we need to remove Python 3.9
Describe the solution you'd like
Remove CI and pyproject.toml support for Python 3.9
Is your feature request related to a problem? Please describe.
Types become a bit simpler to use from Python 3.10 up due to the pipe "|" operator. To simplify adding of type hints and demonstrate that this is a modern tool, we need to remove Python 3.9
Describe the solution you'd like
Remove CI and pyproject.toml support for Python 3.9