The scripts were migrated to the LiteX repository. Any further development will be held there.
Please switch to litex_json2renode and litex_json2dts_zephyr.
For the documentation see: https://github.com/enjoy-digital/litex/wiki/Generate-Renode-simulation and https://github.com/enjoy-digital/litex/wiki/Run-Zephyr-On-Your-SoC.