chore(deps-dev): bump flake8-simplify from 0.20.0 to 0.21.0

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] <[email protected]>

Author: dependabot[bot]

poetry.lock

@@ -68,7 +68,7 @@ flake8-comprehensions = "^3.12.0"
 flake8-docstrings = "^1.7.0"
 flake8-isort = "^6.0.0"
 flake8-pytest-style = "^1.7.2"
-flake8-simplify = "^0.20.0"
+flake8-simplify = ">=0.20,<0.22"
 isort = "^5.11.5"
 pep8-naming = "^0.13.3"
 pyupgrade = "^3.3.1"