add lazy_loader

[PythonFZ]

Use https://github.com/scientific-python/lazy_loader and gives > 20 % speed up on tests.

• fixes XTB does not work with nequip import #50

[PythonFZ]

Edit: should be resolved with znflow v.0.1.11

---

There seems to be an issue with znflow and lazy_loading:

Does not work

with ipsuite.Project() as project:
     model = ipsuite.models.GAP(soap={"cutoff": 0.7}, data=train_selection)

works

ipsuite.models.GAP(data=None, soap={})

with ipsuite.Project() as project:
     model = ipsuite.models.GAP(soap={"cutoff": 0.7}, data=train_selection)

Potential fix

In the zntrack.Node add (can we do this inside znflow) ?:

  def __init_subclass__(cls, **kwargs):
      with znflow.disable_graph():
          return super().__init_subclass__(**kwargs)