remove NCCL pins in build and test environments

[jameslamb]

Description

Contributes to rapidsai/build-planning#102

Some RAPIDS libraries are using ncclCommSplit(), which was introduced in nccl==2.18.1.1. This is part of a series of PRs across RAPIDS updating libraries' pins to nccl>=2.18.1.1 to ensure they get a new-enough version that supports that.

cuvs doesn't have any direct uses of NCCL... it only uses it via raft. This PR proposes removing cuvs's dependency pinnings on NCCL, in favor of just using whatever it gets transitively via raft.

[vyasr]

Does cuvs use nccl directly, or only transitively via raft? I notice that it's not specified in the nccl recipes, and if I search the repo I don't see other references which makes me think it's just via raft. If so, we should just drop it here.

[jameslamb]

Does cuvs use nccl directly, or only transitively via raft? I notice that it's not specified in the nccl recipes, and if I search the repo I don't see other references which makes me think it's just via raft. If so, we should just drop it here.

I searched around and it seems like it's only used transitively through raft.

git grep -i nccl

Looked through the diff of #231 too, and I only see stuff like this:

const raft::comms::nccl_clique& clique = handle.get_nccl_clique_handle();

[vyasr]

Yeah that matches my expectation. Let's see if tests pass. If they do, please update the title and description accordingly and I can approve.

[jameslamb]

Tests look happy! I've updated the title and description here.

Thanks for the nudge, removing these pins will make the next such update a little easier 😁

[jakirkham]

/merge

[jakirkham]

Thanks all! 🙏