[llvm] [mlir] [mlir python] Add nanobind support for standalone dialects. (PR #117922)

[Stella Laurenzo via llvm-commits]

stellaraccident wrote:

Oh man, hit me with this four hours before I'm planning a two week vacation :)

I'll take a look now. Generally supportive. Also supportive of migrating the whole to nanobind given that it is such better performance and ergonomics, but as you say -- a topic for a different day.

https://github.com/llvm/llvm-project/pull/117922