pre-commit normalizes slashes to forward slashes since 2.5.0 (and further back to 1.19.0 for per-hook configuration) there's already a [similar warning for `/*`](https://github.com/pre-commit/pre-commit/blob/2ef29b7f95384f899ede86a370bf2a1c766095b4/pre_commit/clientlib.py#L140-L145) so this should be a fairly beginner-friendly changeset