• List of keywords you searched for before creating this issue: "isnull", "pandas-vet" (read through some of the issues, including one that says pandas-vet is like training wheels; that said, I think it's reasonable to expect it not to flag issues on non-pandas code)
• A minimal code snippet that reproduces the bug: https://github.com/ibis-project/ibis-ml/blob/87889d9857237425544a3a5dc41fce9e1ca7fe5d/ibisml/steps/impute.py#L13 (sorry, I'll try to update this to something more minimal later, but I think you can trigger it by calling .isnull() on literally anything)
• The command you invoked (e.g., ruff /path/to/file.py --fix), ideally including the --isolated flag: Ran though pre-commit hook.
• The current Ruff settings (any relevant sections from your pyproject.toml): PD is selected.
• The current Ruff version (ruff --version): v0.3.2

I did also try type hinting my function (marking col as type ir.Column), but it didn't matter. Looking at the implementation of the rule, it seems to be a naive string match.