Add nightly CI builds with nightly rapids versions

[robertmaynard]

I believe that this is all that is required to build against a nightly rmm version. But this is my first time updating the XGBoost CI.

Fixes https://github.com/dmlc/xgboost/issues/10439

[hcho3]

LGTM.

Note that the nightly CI pipeline is currently blocked by https://github.com/dmlc/xgboost/issues/10752