test-conda-nightly-env: remove ucx-proc exclusion (#742)

Contributes to rapidsai/build-planning#142

Proposes removing the exclusion for `ucx-proc` in the CI job that checks that all projects have produced recent-enough nightlies. See that linked issue for much more detail, but in short:

* there haven't been new `ucx-proc` packages for 2+ years, since conda-forge/ucx-split-feedstock#111
* RAPIDS can safely drop its `ucx-proc` dependency, and other PRs linked to rapidsai/build-planning#142 have done that for the 25.02 release
* `ucx-proc` should not show up in RAPIDS 25.02 environment solves, and so we don't need to carry an exclusion for it in the testing config

Authors:
  - James Lamb (https://github.com/jameslamb)

Approvers:
  - https://github.com/jakirkham
  - Bradley Dice (https://github.com/bdice)

URL: #742

ci/check_conda_nightly_env.py

@@ -18,8 +18,6 @@
     "libxgboost",
     "py-xgboost",
     "xgboost",
-    # TODO: Do we want ucx-proc on rapidsai or from conda-forge?
-    "ucx-proc",
 }
 
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