TST: loosen tolerance in test_krandinit slightly to pass with MKL

[h-vetinari]

Addressing a failure with MKL (c.f. #20472) which looks as follows:

FAILED cluster/tests/test_vq.py::TestKMean::test_krandinit[numpy] - AssertionError: 
Not equal to tolerance rtol=1e-07, atol=0.01

Mismatched elements: 1 / 400 (0.25%)
Max absolute difference among violations: 0.01098377
Max relative difference among violations: 0.00329683

IOW, there's a single element that breaks the atol tolerance by less than 10%.

[rgommers]

Obviously correct, in it goes. Thanks @h-vetinari