[test] Cleanup, reducing PyPI sdist size

fix constraints documentation

properly forward cwd

readme.md: Make Pip the primary installation method

pyproject.toml: Add missing metadata

[test] Fix typo

Publish to PyPI (#510)

check_testing_tool: use vermin to detect version (#508)

Also validate ../../bapctools/resources/config/*.yaml against schema

Add CUE schema for languages.yaml

Fix #509: Use dependency-groups rather than optional-dependencies for development stuff

.pre-commit-config.yaml: Update ruff

pyproject.toml: Cleanup

update code

improve validator tests