ci: Add annotations, more mypy checks

[mdeweerd]

• Improve caching by also saving cache on failures.
• Generate github annotations from pre-commit output (need logToCs.py);
• Install typing dependencies to remove "ignore-missing-imports" on mypy
• Add mdformat plugins to format code.
• Ignore test on cygwin
• Add codespell checks

Note: regarding the annotations, you can have a look in the Files changed tab .
The action summary also has up to 10 error and 10 warning annotations.

[Lucas-C]

Overall, I really like the idea of logToCs.py to convert pre-commit output into a CheckStyle report, so that they can then be exposed as PR annotations.
Good job on crafting this 👍

However, I am NOT favourable towards adding this ~400 lines Python script to this project.
Its purpose is distinct / larger than the scope of this repository, and I do not wish to maintain it.

It would be better as a standalone project! 🙂
If published on Pypi, or in a dedicated GitHub repo usable as a GA workflow script, it could be reused in several GitHub Actions pipelines! And it could have its own README with explanations and even potentially unit tests.

Again, to be clear: I would gladly consider using this tool if it only introduced a few extra lines in .github/workflows/ci.yml, but I'm sorry I won't merge a PR that introduces hundreds of new lines of Python code that are not directly related to pre-commit hooks.

[mdeweerd]

I am not at the step of setting up a package or GA yet - I have set up a project for it though:
https://github.com/mdeweerd/LogToCheckStyle

[mdeweerd]

FYI: https://github.com/mdeweerd/LogToCheckStyle now proposes a Github Action.