Update XGBoost to 2.1.4 (#746)

Blocked on issue: rapidsai/xgboost-feedstock#79

Updates XGBoost to 2.1.4 with CUDA 12.8 support.

Fixes #745

Authors:
  - https://github.com/jakirkham

Approvers:
  - Gil Forsyth (https://github.com/gforsyth)

URL: #746

Author: jakirkham

conda/recipes/versions.yaml

@@ -2,7 +2,7 @@
 
 # Versions for `rapids-xgboost` meta-pkg
 xgboost_version:
-  - '=2.1.3'
+  - '=2.1.4'
 
 cupy_version:
   - '>=12.0.0'