Bump ruff from 0.1.11 to 0.1.15 (#256)

* Bump ruff from 0.1.11 to 0.1.15

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.1.11 to 0.1.15.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@v0.1.11...v0.1.15)

---
updated-dependencies:
- dependency-name: ruff
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

* Fix Ruff errors

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Scott Stevenson <scott@stevenson.io>

src/nb_clean/cli.py

@@ -25,6 +25,7 @@ def expand_directories(paths: list[pathlib.Path]) -> list[pathlib.Path]:
     -------
     List[pathlib.Path]
         Paths with directories expanded into notebooks contained within.
+
     """
     expanded: list[pathlib.Path] = []
     for path in paths: