build: Exclude Jupyter notebooks from Ruff checks

[mplatzer]

Note

Low Risk
Low risk: this only adjusts Ruff configuration to skip *.ipynb files, affecting lint/format coverage but not runtime behavior.

Overview
Updates pyproject.toml Ruff settings to globally exclude Jupyter notebooks by adding extend-exclude = ["*.ipynb"], preventing Ruff from linting/formatting notebook files outside the existing examples/*.ipynb formatting exclusion.

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