k_means_clust - change to remove warning (#10244)

* Replacing the generator with numpy vector operations from lu_decomposition.

* Revert "Replacing the generator with numpy vector operations from lu_decomposition."

This reverts commit ad217c66165898d62b76cc89ba09c2d7049b6448.

* the change removes the warning:
/home/runner/work/Python/Python/machine_learning/k_means_clust.py:236: FutureWarning: The provided callable <function sum at 0x7f20c02034c0> is currently using SeriesGroupBy.sum. In a future version of pandas, the provided callable will be used directly. To keep current behavior pass the string "sum" instead.
     .agg(

And

/home/runner/work/Python/Python/machine_learning/k_means_clust.py:236: FutureWarning: The provided callable <function mean at 0x7f3d7db1c5e0> is currently using SeriesGroupBy.mean. In a future version of pandas, the provided callable will be used directly. To keep current behavior pass the string "mean" instead.
     .agg(