Log Message:
py-xgboost: updated to 1.7.6

1.7.6 Patch Release

Bug Fixes

Fix distributed training with mixed dense and sparse partitions.
Fix monotone constraints on CPU with large trees.
[spark] Make the spark model have the same UID as its estimator
Optimize prediction with QuantileDMatrix.

Document

Improve doxygen
Update the cuDF pip index URL.

Maintenance

Fix tests with pandas 2.0.