[`pylint`] Fix false positives, add missing methods, and support positional-only parameters (`PLE0302`) (#16263)
## Summary
Resolves 3/4 requests in #16217:
- ✅ Remove not special methods: `__cmp__`, `__div__`, `__nonzero__`, and
`__unicode__`.
- ✅ Add special methods: `__next__`, `__buffer__`, `__class_getitem__`,
`__mro_entries__`, `__release_buffer__`, and `__subclasshook__`.
- ✅ Support positional-only arguments.
- ❌ Add support for module functions `__dir__` and `__getattr__`. As
mentioned in the issue the check is scoped for methods rather than
module functions. I am hesitant to expand the scope of this check
without a discussion.
## Test Plan
- Manually confirmed each example file from the issue functioned as
expected.
- Ran cargo nextest to ensure `unexpected_special_method_signature` test
still passed.
Fixes #16217.