Typing, scikit-build core

[inducer]

This now generates a mostly-working stub file, automatically, at build time.

Still to do:

• How to combine types from __init__ and the stub?
  • If kept redundant, add a stub check.
• Make sure the types are actually seen
• Make sure py.typed is installed
• Stub issues:
  • Bogus enum.__str__ import
  • CallbackLifetimeHandle
  • .space returning object
  • Lots of spurious upcast overloads?
• Fix docs
  • Static methods not properly reflected Fix static methods in docs #166
• Fix barvinok build script

Closes #156.

x-ref: wjakob/nanobind#1055
x-ref: wjakob/nanobind#1061

[inducer]

Based on inspection, the changes to the loopy tutorial output appear to have been equivalent, so I am not considering that a merge obstacle.