Introduce ruff pre-commit hook

• Get rid of isort, pylint, pyupgrade pyproject, pre-commit, gitlab-ci configurations
• Introduce ruff pyproject, pre-commit, gitlab-ci configurations
• Makefile: replace pylint with ruff (to be honest, I don’t see the point of make rules for pre-commit hooks).
• Replace black with ruff-format
• Fix ruff reports
  • Use pathlib
  • Define custom exceptions to support new Pylint ... (#200 - closed)
• Update hooks used in CONTRIBUTING.md § pre-commit