Update linters: remove flake8, add ruff, update cython-lint

[vyasr]

Description

The cython-lint change is necessary to unblock runs after the Cython 3.0 update, but it is also a QOL improvement that allows us to remove flake8 usage in Cython files since cython-lint now covers a superset of what flake8 could do for Cython. ruff is (nearly) a superset of flake8 for pure Python and has a wide range of advantages, so this switch is beneficial as well.

cf. rapidsai/cudf#13699

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[vyasr]

/merge