Update shebang for python 3

[DannyCork]

updated to python3

as per readme "Scripts are written for Python 3.6+"

[opsdisk]

Hey @DannyCork - appreciate you taking the time to create a PR. Man, I had to read up on this one! I've been putting that she-bang line in scripts for years, but forgot why.

Did some research, and it's what PEP 394 recommends for virtual environments (which I've always used and probably why I gravitated toward it) - https://peps.python.org/pep-0394/#for-python-script-publishers

In general, Python stuff should be run in a virtual environment or in a container these days. I have been meaning to push a Dockerfile to the repo with a Python3 base image. In addition, with Python2 EOL as well (and hopefully the elimination of python vs python3 stuff alias shenanigans)...I don't see a strong need to specify the version in that line.

I will chew on this one a bit more and do some more reading.

Other links:

• https://stackoverflow.com/questions/6908143/should-i-put-shebang-in-python-scripts-and-what-form-should-it-take
• https://discuss.python.org/t/pep-394-clarify-bullet-for-usr-bin-env-python/7953

[opsdisk]

Appreciate the thought provoking PR @DannyCork, but after reviewing the "For Python script publishers" recommendations in https://peps.python.org/pep-0394/#recommendation again, I'm going to leave it as is. I do recommend using a virtual environment, running it in a container is possible (I plan to provide a Dockerfile soon), and in due time I think python will just come to mean python3 and a specific numerical distinction won't be necessary.

Applications designed exclusively for a specific environment (such as a container or virtual environment) may continue to use the python command name.