docs: fix spacing of k-means code snippet

[arwas11]

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  • screen/9c8bfeRerKkCt3h
  • screen/4B6ZsSVYaDR3o3c
  • screen/7FdJPXVpGNC2z7N
    Fixes #412723079 🦕

[arwas11]

Unrelated e2e failure:

=========================== short test summary info ============================
FAILED tests/system/small/test_dataframe.py::test_series_binop_axis_index[le]
FAILED tests/system/small/test_dataframe.py::test_join_param_on[inner] - goog...