Bugfix/makefile

[nacezavrtanik]

• make clean-build, and by extension make clean (in the specific order the subcommands are defined) would fail if there existed a .tox directory.

  • Reason: The .tox directory contains subdirectories ending with "egg", which make clean-build would attempt to delete, without the -r flag.

• make clean-test now removes the .ruff_cache and .pytest_cache directories as well.

  • The .pytest_cache dir does not get created if testing with tox directly, but since pytest is specfied as a dev dependency I figured some people might run tests simply using pytest.
  • The ruff_cache is created when running tox, since the default tox behavior runs linting and formatting as well now. While it might not make too much sense for the make clean-test command to remove actual formatting artifacts, one would still want to remove the artifacts, and this is the place it makes the most sense to do it, since make test creates the artifacts in the first place.

• I also updated the make help to reflect the actual behavior.