Gelidum

Fixes
- Add support for cpython 3.13 and pypy 3.10.
- Add pyproject.toml specifying that this package uses setuptools.

Features
- Adding `original_obj` attribute to **frozen by copying objects** to get the original object.
This original_obj attribute is only present in frozen objects, not in their attributes even if they are objects, e.g.
python
from gelidum import freeze

class DummyChild(object):
def __init__(self, value: int):
self.attr = value

class Dummy(object):
def __init__(self, child: DummyChild):
self.child = child

dummy_child = DummyChild(value=1)
dummy = Dummy(child=dummy_child)
frozen_dummy = freeze(dummy, on_freeze="copy")

assert(frozen_dummy.original_obj.__class__ == dummy.__class__)
assert(id(frozen_dummy.original_obj) == id(dummy))
assert(frozen_dummy.child.original_obj == None)

Fixes
- Include support for python 3.12.
- Add cpython 3.12 to CI.

Features
- Beta support for freezing [numpy arrays](https://numpy.org/doc/stable/reference/arrays.html).

Features
- Allow freezing of objects whose class has \_\_slots\_\_.