Update xgboost to 2.1.1

[raydouglass]

The xgboost version was increased for 24.08 in rapidsai/xgboost-feedstock#67, so update to match here.

[jakirkham]

Listing the package we will want to include from comment ( rapidsai/xgboost-feedstock#70 (comment) ) below:

Went through the CI logs and scraped out these packages as the ones we need to copy to rapidsai

libxgboost-2.1.1-rapidsai_h0f6b306_4.conda
libxgboost-2.1.1-rapidsai_h207c33c_4.conda
libxgboost-2.1.1-rapidsai_h5b1fefd_4.conda
libxgboost-2.1.1-rapidsai_hc551fd8_4.conda
py-xgboost-2.1.1-rapidsai_pyh258eea3_4.conda
py-xgboost-2.1.1-rapidsai_pyh55089e7_4.conda
py-xgboost-2.1.1-rapidsai_pyhba16b86_4.conda
py-xgboost-2.1.1-rapidsai_pyhf7e6b63_4.conda
xgboost-2.1.1-rapidsai_pyh083a5a1_4.conda
xgboost-2.1.1-rapidsai_pyh26c0410_4.conda