devel/py-orjson: Update to 3.9.10

• Switch to PEP517 build framework and remove the now obsolete pre-PEP517 workarounds. Building the port for non-default Python flavors should now be possible as well.

• Add test suite to make future QA easier.

Changelog since 3.8.0:

https://github.com/ijl/orjson/blob/3.9.10/CHANGELOG.md

PR: 275701
Approved by: Ivan Rozhuk (maintainer)