Upgrade tooling

[Batalex]

Changes

• Align our tooling with our other products
• Drop support for Python 3.8 and 3.9. Our default runtime is Jammy, which comes with 3.10
  • upgraded type hints for a more modern code base
• Fix compatibility with Python 3.11+
• The previous flake8 configuration was not properly enforced for some reason. Migrating to ruff made me fix a bunch of violations (which means adding low value docstrings, to be honest)

We have some unused or outdated stuff that we could remove:

• utils.py
  • union(): we use it for PropertyFile objects which are only one level data structure AFAICT. The | operator is sufficient
  • _check(): used in one place in filter_none, trivial to inline this
  • mkdir()
  • create_dir_if_not_exists()
• exceptions.py
  • K8sClusterNotReachable
• services.py
  • InMemoryAccountRegistry is only used in unit tests, maybe it could go there? We would not have to distribute it in the package

[deusebio]

Looks great @Batalex ! Thank you for this chore work!!!

[theoctober19th]

Great work publishing spark8t in PyPi! The PR looks superb!

[Batalex]

@deusebio, @theoctober19th thanks for the reviews! What are your thoughts on removing the unused elements I listed in the description?

[theoctober19th]

@Batalex I'm fine with updating / refactoring places where the code is not used / relevant anymore, (eg, unused exceptions, functions which can be replaced with simple inbuilt structures, etc.). One thing I'm not quite sure about is the purpose of the InMemoryAccountRegistry. I'd like to hear @welpaolo and @deusebio's views on the original motive behind this registry before I comment anything on that particular piece of code.