add tests for ggml generator

[jmartin-tech]

• Adds test for GGML initialization validation
• Refactors pyproject.toml to make dev and test dependencies optional
  • Add pyproject.toml optional-dependencies section
  • Add # comment line support for requirements.txt in validation test
  • Update validation test to include optional-dependencies

Item to consider here, should the dependencies validation test be revised to validate sections noted in requirements.txt are consistent with pyproject.toml? Having asked this I posit the value for the changes is in pyproject.toml no longer requiring dev or test dependencies during a pip install garak and sections in requirements.txt is just syntactic sugar.

[leondz]

Looks good, just a couple of questions