Ruff top-level linter settings are deprecated in favour of lint section

[cclauss]

Remove the following warnings:

warning: The top-level linter settings are deprecated in favour of their counterparts in the lint section. Please update the following options in pyproject.toml:

• 'dummy-variable-rgx' -> 'lint.dummy-variable-rgx'
• 'fixable' -> 'lint.fixable'
• 'ignore' -> 'lint.ignore'
• 'select' -> 'lint.select'
• 'unfixable' -> 'lint.unfixable'
• 'mccabe' -> 'lint.mccabe'

[github-actions]

This pull request has been marked as stale. It will be closed in 14 days if no further activity occurs.

[cclauss]

Please have a human being review the proposed changes instead of a bot.

[cclauss]

@brucearctor

[github-actions]

This pull request has been marked as stale. It will be closed in 14 days if no further activity occurs.

[cclauss]

Let's get a human do code review instead of a machine.

[charliermarsh]

@cclauss -- Thank you, I applied this in https://github.com/astral-sh/ruff-action.