Use Python venv in CI tests

[jafingerhut]

Without this, I have seen many failures recently on Ubuntu 22.04 that I do not know the root cause of, but using a venv gives consistently passing results.

[antoninbas]

This looks good to me, but I think you should consider using https://github.com/actions/setup-python as a follow up. This way you can control which version of python to test with (you can add multiple versions to the test matrix as well). I'm assuming Python-based projects which use Github Actions for testing typically use this core action to set up the environment.

[jafingerhut]

you should consider using https://github.com/actions/setup-python as a follow up. This way you can control which version of python to test with (you can add multiple versions to the test matrix as well). I'm assuming Python-based projects which use Github Actions for testing typically use this core action to set up the environment.

Thanks. I will create an issue with your suggestion, to track it for future implementation, but merge this PR as is.