ollama: add pydocstyle linting for ollama (#27686)
Description: add lint docstrings for ollama module
Issue: the issue https://github.com/langchain-ai/langchain/issues/23188
@baskaryan
test: ruff check passed.
<img width="311" alt="e94c68ffa93dd518297a95a93de5217"
src="https://github.com/user-attachments/assets/e96bf721-e0e3-44de-a50e-206603de398e">
Co-authored-by: Erick Friis <erick@langchain.dev>
