Libigl

- Libigl bumped to 2.4.0
- builds on Python 3.11 (via bumping numpyeigen)
- cleaned up CMake
- cleaned up build scripts for pip install and cibuildwheels
- improved coverage of libigl functions
- `writeDMAT`
- `moments`
- `direct_delta_mush`

Install over at pip:

pip install libigl==2.4.1

The python bindings are now feature-complete