Update json requirement from ~> 1.8 to ~> 2.3

Updates the requirements on [json](https://github.com/flori/json) to permit the latest version.
- [Release notes](https://github.com/flori/json/releases)
- [Changelog](https://github.com/flori/json/blob/master/CHANGES.md)
- [Commits](https://github.com/flori/json/compare/v1.8.6...v2.3.1

)

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