Migrate from ujson to orjson

[raruler]

ujson is currently not supported, and is in maintenance mode

[!WARNING] UltraJSON's architecture is fundamentally ill-suited to making changes without risk of introducing new security vulnerabilities. As a result, this library has been put into a maintenance-only mode. Support for new Python versions will be added and critical bugs and security issues will still be fixed but all other changes will be rejected. Users are encouraged to migrate to orjson which is both much faster and less likely to introduce a surprise buffer overflow vulnerability in the future.
https://pypi.org/project/ujson/

'orjson' -> https://pypi.org/project/orjson/

hopefully it's a drop-in replacement