Github Actions updates

[james-s-w-clark]

I like this project, and saw you use Github Actions.
Saw there's a couple things that could be simplier/more efficient, so thought I'd raise a PR :)

I tried testing locally with act but it's getting stuck downloading apt updates, so I thought I'd raise a PR.

Approval is needed to allow the Github Action workflow, thanks 👍

[acabal]

We want to specify a version of Ubuntu because the SE server runs on a specific version and we have to make sure the tools work on that version. Can you undo the move to ubuntu-latest?

[acabal]

Why did we remove -dev from here, but in a ad722fc we specified 3.x-dev?

[james-s-w-clark]

I tried 3.x-dev as https://github.com/actions/setup-python#available-versions-of-python says that it'd get the latest patch version thanks to dev. It didn't exist in the manifest when I tried running the action locally with act though:

::error::Version 3.x-dev with arch x64 not found%0AThe list of all available versions can be found here: https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json

3.x seems to be the most common version I see for Github Actions, e.g. in the first basic snippet here https://github.com/actions/setup-python#usage.

One strange thing: https://github.com/actions/setup-python/releases/tag/v4.0.0 has a commit to fix the 3.x-dev syntax. I think the bug is unrelated to not parsing the version and finding best patch version in the manifest though 🤔

[james-s-w-clark]

3.11-dev works - it finds 3.11.0-beta.3

3.x gets python-3.10.5-linux-20.04-x64.tar.gz

Are you happy with 3.x (auto incrementing, and more stable), or prefer a fixed version with dev (bleeding edge for a short time, more maintenance, less stable)?

[acabal]

OK, this looks good, thanks! Let's stick with the more stable version of Python.