Log Message:
py-rapidjson: updated to 0.9.3

0.9.3:
* Fix access to ``Encoder`` instance attributes

0.9.2:
* Use `current master`__ version of rapidjson
* Enable GH Actions-based test workflow
* Produce Python 3.9 wheels, disable testing under Python < 3.6
* Make the character used for indentation in pretty mode a parameter
* Handle wider precision range in timestamps fractional seconds
* Add comparison benchmarks against orjson and hyperjson