Use system's Python interpreter instead of one, obtained from env

[OlehAhieienko]

Issue: Python dependencies are installed using package manager (-> globally) yet scripts in repository are obtaining path to interpreter from env, which, likely, will point to user's virtual environment, hence, missing dependencies.

Fix: use absolute path to system's Python interpreter in shebang (#!/usr/bin/python3).

[learmj]

Would it not be justified to say that if a user is using their own virtual env, they need to be responsible for ensuring it contains all the dependencies the tool needs? If not, why not?

[OlehAhieienko]

User may have own venv activated by default/automatically, without realizing there are missing dependencies (that should already be installed on system, if user follows instructions in readme).