[ruff] add fix safety section (RUF007)

crates/ruff_linter/src/rules/ruff/rules/zip_instead_of_pairwise.rs

@@ -29,6 +29,14 @@ use crate::{checkers::ast::Checker, importer::ImportRequest};
 /// pairwise(letters)  # ("A", "B"), ("B", "C"), ("C", "D")
 /// ```
 ///
+/// ## Fix safety
+///
+/// The fix is always marked unsafe because it assumes that slicing an object
+/// (e.g., `obj[1:]`) produces a value with the same type and iteration behavior
+/// as the original object, which is not guaranteed for user-defined types that
+/// override `__getitem__` without properly handling slices. Moreover, the fix
+/// could delete comments.
+///
 /// ## References
 /// - [Python documentation: `itertools.pairwise`](https://docs.python.org/3/library/itertools.html#itertools.pairwise)
 #[derive(ViolationMetadata)]