v1.16.2

Changes:

• Perform appropriate signed/unsigned min/max gather step.
• Migrate from setuptools to scikit-build-core.
• make isn't available by default, but it's currently needed to build.
• Consolidate build and host reqs in conda meta.yaml.
• Tweaks for driving scikit-build
• Fix SDS stacking of empty SDS
• UT testing improvements
• The new ut gtest emulation allows for discovering each individual test,...
• Improve gtest emulation
• Don't crash if no riptable - just exit with failure
• Invoke riptable.tests via pytest, not riptable.tests.run