Remove nx-cugraph from cugraph

[eriknw]

I believe this is needed to remove nx-cugraph from the cugraph repo being done in rapidsai/cugraph#4756

This is a subset of the changes @jameslamb is making in #417. Does it make sense to do this change for nx-cugraph and cugraph-gnn independently (how close is cugraph-gnn to being removed?)? Should we also add nx-cugraph as done in that PR? Anything else?

@nv-rliu @jameslamb @rlratzel

[jameslamb]

This is not the right fix. Don't you still want nx-cugraph to be buildable with devcontainers? Even if we don't add devcontainer CI / devcontainer configs in the https://github.com/rapidsai/nx-cugraph repo, I think it'd still be useful to have that support here in the unified devcontainer... so you could make a change in cugraph and then test how it affects nx-cugraph.

That is why in #417, I added something like this:

- name: nx-cugraph
  path: nx-cugraph
  git: {<<: *git_defaults, repo: nx-cugraph}
  python:
    - name: nx-cugraph
      sub_dir: .
      args: {install: *rapids_build_backend_args}

And please see the other change there... any time you change the content of something in features/ here, you need to bump it's version.

Once those are addressed, I support moving this PR forward and not trying to wait on the GNN projects. I'd hoped to be able to do this all at once, but cugraph-gnn needs a bit more work.

[jameslamb]

Also note that the CI failures here weren't because of your changes, and should resolve on a re-run now that rapidsai/raft#2490 was merged.

[eriknw]

Thanks @jameslamb I suspected we needed to make those changes, thanks for explaining :) . Updated.

[trxcllnt]

@jameslamb Even if we don't add devcontainer CI / devcontainer configs in the nx-cugraph repo

We should add devcontainers to the new nx-cugraph repo. Aside from them being a convenient way to work on a project for outside contributors, they also help ensure nx-cugraph changes don't break devcontainer and DLFW builds.

[jameslamb]

We should add devcontainers to the new nx-cugraph repo

Great, let's do that. Want to put up a PR at https://github.com/rapidsai/nx-cugraph?

[jameslamb]

Believe CI errors like this:

/home/coder/cuvs/cpp/src/neighbors/iface/iface.hpp(176): error: incomplete type is not allowed

1 error detected in the compilation of "/home/coder/cuvs/cpp/src/neighbors/iface/iface_cagra_float_uint32_t.cu".

(build link)

Should be fixed by rapidsai/cuvs#467

[jameslamb]

I put up a PR to add devcontainers CI jobs for nx-cugraph: rapidsai/nx-cugraph#25

[jameslamb]

Even though this change is also covered in #417, CI just started over there and takes a couple hours to run.

Merging this to unblock rapidsai/cugraph#4756 and rapidsai/nx-cugraph#25