Using the brand new isolated_environment functionality in
test_helper.bash to set up a fresh and clean environment where we can
use pyenv to install a clean python version, and then check whether we
are getting an automatic rehash after pip install.
We are checking:
- pip
- pip3
- pip3.12
- python -m pip
- python3 -m pip
- python3.12 -m pip
for automatic rehash.