Log Message:
py-xgboost: updated to 2.1.1

The 2.1.1 patch release make the following bug fixes:

[Dask] Disable broadcast in the scatter call so that predict function won't hang
[Dask] Handle empty partitions correctly
Fix federated learning for the encrypted GRPC backend
Fix a race condition in column splitter
Gracefully handle cases where system files like /sys/fs/cgroup/cpu.max are not \ 
readable by the user
Fix build and C++ tests for FreeBSD
Clarify the requirement Pandas 1.2+
More robust endianness detection in R package build

In addition, it contains several enhancements:

Publish JVM packages targeting Linux ARM64
Publish a CPU-only wheel under name xgboost-cpu
Support building with CUDA Toolkit 12.5 and latest CCCL