Bump flake8-simplify from 0.20.0 to 0.21.0 (#420)

Bumps [flake8-simplify](https://github.com/MartinThoma/flake8-simplify) from 0.20.0 to 0.21.0.
- [Release notes](https://github.com/MartinThoma/flake8-simplify/releases)
- [Changelog](https://github.com/MartinThoma/flake8-simplify/blob/main/CHANGELOG.md)
- [Commits](https://github.com/MartinThoma/flake8-simplify/commits/0.21.0)

---
updated-dependencies:
- dependency-name: flake8-simplify
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

pyproject.toml

@@ -37,7 +37,7 @@ flake8 = "^5.0.4"
 flake8-bugbear = "^23.3.12"
 flake8-comprehensions = "^3.14.0"
 flake8-docstrings = "^1.7.0"
-flake8-simplify = "^0.20.0"
+flake8-simplify = "^0.21.0"
 flake8-use-fstring = "^1.4"
 flake8-use-pathlib = "^0.3.0"
 isort = "^5.12.0"