[clang] [libclang/python] Simplify __eq__ operators (PR #140540)

[Vlad Serebrennikov via cfe-commits]

https://github.com/Endilll commented:

Why does the diff show that you add `__ne__` operator, even though it's already present? What am I missing?
https://github.com/llvm/llvm-project/blob/f3d36b15f6dde7ca2d080279274d5d0f4bfc8c30/clang/bindings/python/clang/cindex.py#L397-L403

https://github.com/llvm/llvm-project/pull/140540