Updates the requirements on [isort](https://github.com/pycqa/isort) to permit the latest version.
- [Release notes](https://github.com/pycqa/isort/releases)
- [Changelog](https://github.com/PyCQA/isort/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/pycqa/isort/compare/4.3.4...5.6.4)

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

• Commit ab4237f
• #268: Update isort requirement from ~=4.3.4 to ~=5.6.4
• Branch develop

dependabot[bot]