Replaced python2 with python3

[ummthespruce]

Prerequisite Checklist

• Read the contribution guidelines regarding submitting new changes to the project;
• Tested your changes against relevant architectures and platforms;
• Updated relevant documentation (if needed).

Description of changes

[teodutu]

The reason we're using Python 2 is that students will find it easier to write python2 -c 'print ...' rather than python3 -c 'import sys; sys.stdout.buffer.write(.... We're targeting 1st year students, they'll find it difficult to understand why print(...) doesn't work or how sys.stdout.buffer.write() differs.

[StefanJum]

The reason we're using Python 2 is that students will find it easier to write python2 -c 'print ...' rather than python3 -c 'import sys; sys.stdout.buffer.write(.... We're targeting 1st year students, they'll find it difficult to understand why print(...) doesn't work or how sys.stdout.buffer.write() differs.

Python2 is deprecated (has been for a long time), and if you want it on ubuntu 24 you need to build it yourself.
The student vms will be ubuntu 24. I think we can safely go for python3 only, it's one line of code that can pe copy pasted every time, and it is copy pasted every time for python2 too.

[teodutu]

Ok now it makes more sense @StefanJum. Python3 it is.

[teodutu]

@ummthespruce before we merge this, please squash your commits and then reword the commit message according to the guidelines: https://github.com/cs-pub-ro/hardware-software-interface/blob/main/CONTRIBUTING.md#commits