Since tutor v19.0.3, the tar.gz package on pypi includes a venv/ directory

[regisb]

Bug description

In Tutor 20.0.0 (and since 19.0.3), the package archives include a venv/ directory, which should not be there:

https://files.pythonhosted.org/packages/42/0b/32a12b9e703a2bf6717581bf7c3224840880e1f316d09664b86867efc699/tutor-20.0.0.tar.gz
https://files.pythonhosted.org/packages/56/7d/ee6f5a044ec2fe449228e648f57beba3949d0dd1bbda6afd1dcfd31b4d4a/tutor-19.0.3.tar.gz

How to reproduce

Download the tar.gz files from pypi: https://pypi.org/project/tutor/20.0.0/#files
Decompress; the archives contains the following files:

LICENSE.txt  PKG-INFO  pyproject.toml  README.rst  requirements  tutor  venv

The venv directory really shouldn't be there.