Update xgboost in the requirements to at least 1.7.6

[arturdaraujo]

Most of the Xgboost packages in Conda that have compatibility with Cuda is in this version of Xgboost. My CUDA is version 11.8 and I can't run GPU on versions of Xgboost lower than that on Python 3.11.

This version doesn't change much of its API as the version 2.0.0 of Xgboost. This would greatly improve the package compatibility.

https://anaconda.org/conda-forge/xgboost/files?page=3&type=conda&version=1.7.6