Update flake8-isort requirement from <5.0.0,>=4.2.0 to >=4.2.0,<6.0.0

Updates the requirements on [flake8-isort](https://github.com/gforcada/flake8-isort) to permit the latest version.
- [Release notes](https://github.com/gforcada/flake8-isort/releases)
- [Changelog](https://github.com/gforcada/flake8-isort/blob/master/CHANGES.rst)
- [Commits](https://github.com/gforcada/flake8-isort/compare/4.2.0...5.0.3)

---
updated-dependencies:
- dependency-name: flake8-isort
  dependency-type: direct:production
...

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

pyproject.toml

@@ -61,7 +61,7 @@ check = [
     "flake8<6",
     "flake8-black",
     "flake8-colors",
-    "flake8-isort>=4.2.0,<5.0.0",
+    "flake8-isort>=4.2.0,<6.0.0",
     "flake8-pyi",
     "flake8-typing-imports",
     "docutils",