Enforce Ruff docstring rules

[anakin87]

In Haystack, we have these ruff rules enabled for docstrings:

  "D102",   # Missing docstring in public method
  "D103",   # Missing docstring in public function
  "D205",   # 1 blank line required between summary line and description
  "D209",   # Closing triple quotes go to new line
  "D213",   # summary lines must be positioned on the second physical line of the docstring
  "D417",   # undocumented-parameter
  "D419",   # undocumented-returns

We should do something similar on core integrations:

• modify pyproject.toml files to enable these rules
• fix errors emerging from enabling these rules
• enable these rules on pyproject.toml template: https://github.com/deepset-ai/haystack-core-integrations/blob/main/scripts/utils/templates/pyproject.toml

I recommend opening more than one PR to ease review but not one for each integration

[passionworkeer]

Great initiative to enforce docstring consistency! A few suggestions for the implementation:

1. Incremental rollout: Consider enabling rules one at a time (e.g., start with D102, D103) to avoid overwhelming contributors.

2. Pre-commit hook: Add ruff to pre-commit-config.yaml so issues are caught before commit:
   `yaml

• repo: https://github.com/astral-sh/ruff-pre-commit
  hooks:
  • id: ruff
    args: [--fix]
    `

3. Template first: Updating the pyproject.toml template first ensures new integrations follow the rules from day one.

4. CI parallelization: Since this affects many integrations, consider using pytest-xdist to speed up the linting phase in CI.

Looking forward to seeing this improvement land!