Tests require python and pytest which suffer from the usual python issues of minor revision compatibility

[Smit-tay]

Currently tests are performed via Python pytest scripts.

This introduces an unnecessary - not to mention precarious - requirement that the user have Python installed. Python suffers (more than many other languages) from rapid changes to functionality. This makes keeping the test scripts compatible with the latest Python version a challenge, and introduces an unnecessary (and unwanted) burden upon maintainers and developers to resolve issues related to Python default versions.

Recommended: Move all testing to CMake CTest