* [CI] Update RAPIDS to latest stable * [CI] Use rapidsai stable channel; fix syntax errors in Dockerfile.gpu * Don't combine astype() with loc() * Work around https://github.com/dmlc/xgboost/issues/10181 * Fix formatting * Fix test --------- Co-authored-by: hcho3 <hcho3@users.noreply.github.com> Co-authored-by: Hyunsu Cho <chohyu01@cs.washington.edu>