Linker error was:

Undefined symbols for architecture arm64:
  "MaterialLib::Solids::Ehlers::StateVariables<2>::getEquivalentPlasticStrain() const", referenced from:
      vtable for MaterialLib::Solids::Ehlers::StateVariables<2> in unity_0_cxx.cxx.o
  "MaterialLib::Solids::Ehlers::StateVariables<3>::getEquivalentPlasticStrain() const", referenced from:
      vtable for MaterialLib::Solids::Ehlers::StateVariables<3> in
      unity_0_cxx.cxx.o

Is not supported for CMAKE_OSX_DEPLOYMENT_TARGET=10.15

[ci] Upload wheel to GitLab registry.

Implementation from
https://github.com/scikit-build/cmake-python-distributions

Was coupled to OGS_USE_PYTHON before.

```
pip install .
pytest
```

Build with:

```
pip install .
```

Theis notebookv2

See merge request ogs/ogs!4242

Added unit tests for googletest Eigen predicate

Closes #3313

See merge request ogs/ogs!4276

Fix warnings

See merge request ogs/ogs!4279

 - Avoid shadowing,

 - Unify declaration/definition name.

Fix c++ warnings, documentation and spelling

See merge request ogs/ogs!4278