Update ruff requirement from >=0.15.12 to >=0.15.13

Updates the requirements on [ruff](https://github.com/astral-sh/ruff) to permit the latest version.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/CHANGELOG.md)
- [Commits](astral-sh/ruff@0.15.12...0.15.13)

---
updated-dependencies:
- dependency-name: ruff
  dependency-version: 0.15.13
  dependency-type: direct:development
...

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

Author: dependabot[bot]

requirements-dev.txt

@@ -3,7 +3,7 @@ pytest
 pytest-cov
 pytest-mockito
 robotstatuschecker
-ruff >= 0.15.12
+ruff >= 0.15.13
 robotframework-robocop >= 8.0.0
 invoke >= 3.0.3
 twine