Remove references to cugraph-ops

[jameslamb]

Description

cugraph recently dropped its last remaining uses of cugraph-ops (rapidsai/cugraph#4784).

cugraph-gnn packages are planning to do the same in the 25.02 release (rapidsai/cugraph-gnn#81).

All references to cugraph-ops, libcugraphops, and pylibcugraphops here (except historical references like CHANGELOG entries) should be removed.

Benefits of this work

• frees up CI resources for the rest of RAPIDS, via enabling us to tear down nightly builds / tests for https://github.com/rapidsai/cugraph-ops
• unblocks lots of other simplification of building and publishing processes, see https://github.com/rapidsai/build-infra/issues/155

Acceptance Criteria

• this repo does not depend on any cugraph-ops packages, docs artifacts, or source code

Approach

See the references via this:

git grep -i -E 'cugraphops|cugraph\-ops|cugraph_ops'

Notes

N/A