[llvm] [mlir] [mlir python] Port Python core code to nanobind. (PR #118583)

[Jacques Pienaar via llvm-commits]

jpienaar wrote:

Sounds good, let me follow up and do a quick check. I'll give a more formal review (did a review and looked fine but I'll go over again)

https://github.com/llvm/llvm-project/pull/118583