Clarify Python version deprecation policy

[LukeMoll]

🎉 Happy issue #200 ! 🎈

The rationale behind supporting old versions of Python should be included in the documentation so that decisions regarding when to drop support can be made. The initial decision was based on:

The minimum (oldest) Python version HackSoc.org will support is the latest version available from the official Ubuntu repositories on the oldest supported LTS.

At the time (late 2021), Ubuntu 16.04 LTS Xenial Xerus was out of support (5 years from 04/2016), so the next-oldest was Ubuntu 18.04 LTS Bionic Beaver (due to go out of support in 04/2023). The latest version of python3 available in the bionic repository is python3.6.5, so HackSoc.org must support at least Python 3.6.

Before documenting this policy, it may be reviewed and changed, the above justification is given as a starting point.

[LukeMoll]

Additionally, 3.6 is now considered end-of-life by Python¹. A simpler policy could be to support the oldest version that is not EOL.

It is possible (but should be confirmed) that any Ubuntu LTS still in support would ensure that it always provides an in-life Python version in its repositories. If this is not the case, then the policy should consider the likelihood of users being in this situation without being able to upgrade themselves.

Footnotes

1. https://endoflife.date/python ↩

[LukeMoll]

To help contributors and inform them that they need to upgrade their system, a warning could be printed if the code is being run on a version of Python no longer supported by this repository.