[wheel] set MLIR_BINDINGS_PYTHON_NB_DOMAIN correctly

[makslevental]

See llvm/lighthouse#14

[makslevental]

cc @banach-space @rolfmorel

[rolfmorel]

Thanks @makslevental!

llvm/lighthouse#14 demonstrates a general compatibility issue with the mlir-python-bindings package (i.e. not lighthouse related).

EDIT: will build the torch_mlir package from this branch later today and report back if it resolves the problem.

[rolfmorel]

Great -- that resolves it! Confirmation that this fix indeed works:

$ build_tools/python_deploy/build_linux_packages.sh
...
$ uv venv -p 3.12
...
$ uv pip install -f https://llvm.github.io/eudsl mlir-python-bindings                                            
...
 + mlir-python-bindings==20251121+f9696949c
$ uv pip install build_tools/python_deploy/wheelhouse/torch_mlir-0.0.1-cp312-cp312-linux_x86_64.whl  # Couldn't be bothered to specify the version...
...
$ uv pip install torch
...
$ uv run python  # execute the minimal reproducer from llvm/lighthouse#14:
>>> from mlir import ir
>>> from torch_mlir  import fx
>>> print(ir.Context)
<class 'mlir._mlir_libs._site_initialize.<locals>.Context'>

If this could go in soon, that would be much appreciated! As it stands, this issue is blocking bumping torch-mlir on lighthouse (and some PRs there, e.g. llvm/lighthouse#22).

CC @banach-space @rengolin