Gaussian orbital example + test

[joshkamm]

• Add an example of using a gaussian orbital basis via libcint
• Update the main function to infer if a gaussian orbital basis is desired based on the input files or a command line option
• Update pytest and pixi configuration to include a gaussian orbital basis test in github action CI

[joshkamm]

Paul live changes dump:

examples/main.cpp
examples/CMakeLists to add dependence on cintw near the top and further down
hardcoded line with linking libcint