pip: update ruff requirement in the pip-updates group

Updates the requirements on [ruff](https://github.com/astral-sh/ruff) to permit the latest version.

Updates `ruff` to 0.14.13
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@0.14.11...0.14.13)

---
updated-dependencies:
- dependency-name: ruff
  dependency-version: 0.14.13
  dependency-type: direct:production
  dependency-group: pip-updates
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

test-requirements.txt

@@ -1,4 +1,4 @@
-ruff~=0.14.11
+ruff~=0.14.13
 coverage>=4.0,!=4.4 # Apache-2.0
 python-subunit>=0.0.18 # Apache-2.0/BSD
 stestr>=1.0.0 # Apache-2.0