Update all dependencies 2025-10

While !30 only updates one particular dependency (and to a particular version), this changeset updates all dependencies to their most recent versions.

 1. Updated all PyObject type aliases to Py
 2. Replaced .to_object(py) with .into_py(py) or .into() where appropriate
 3. Replaced .to_object(py) with .into_py(py) or .into() where appropriate
 4. Updated PyList::empty_bound() to PyList::empty()
 5. Updated PyDict::new_bound() to PyDict::new()
 6. Updated PySet::empty_bound() to PySet::empty()
 7. Updated PyNone::get_bound(py).to_object(py) to py.None()
 8. Updated PyBuffer::::get_bound() to PyBuffer::::get()
 9. Updated Python::allow_threads() to py.allow_threads() (method call)
10. Updated py.get_type_bound() to py.get_type()

Note that the AI this time wrote different code than in #30 (closed) - into() vs unbind(). I like this version here a bit better since it's slightly shorter, and OpenAI tells me they should both be doing the same under the hood, but I am not so sure of this.

Co-authored-by: aider (anthropic/claude-sonnet-4-5-20250929) aider@aider.chat