Are you sure there wasn't an existing virtual environment at .venv? By default, venv does not upgrade an existing environment. Try deleting the .venv directory first, assuming there is nothing in the environment you want to save. Otherwise you could try debugging the shell steps with the shell command:

set -x

and, if necessary, debugging the python environment with:

python3 -m test.pythoninfo

https://docs.python.org/3.9/library/venv.html