Fix linter conflict

[edwardchalstrey1]

When saving files in an IDE (e.g. VSCode/Antigravity) with the Ruff plugin installed and format-on-save enabled, the formatter automatically reformats Python slices that contain complex expressions (e.g., changing rst[src_idx:src_idx + 40] to rst[src_idx : src_idx + 40]). This is intentional behavior by modern formatters (like Black and Ruff) to improve readability and complies with PEP 8.

However, the pre-commit hooks for both ruff and flake8 enforce the pycodestyle rule E203 (whitespace before ':'), which strictly disallows this spacing. As a result, files formatted correctly by the IDE were being rejected by the pre-commit linters, blocking commits. This could be an annoying blocker other developers may face.

Description of the changes in this PR

This PR adds E203 to the ignore list for both linters:

• Updated pyproject.toml to ignore E203 in [tool.ruff.lint].
• Updated .flake8 to include extend-ignore = E203.
• Saved one file as an example and was able to commit the change without the pre-commit complaining

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