Default random_state for KMeans and FuzzyCMeans should be None

[vnmabus]

Bug description summary

The default behavior of KMeans and FuzzyCMeans when no random_state is passed should be to not use a fixed seed, as it is done in scikit-learn. Somehow, the current behavior is having a fixed seed (0).

Code to reproduce the bug

from skfda.ml.clustering import KMeans

clusterer = KMeans()
print(clusterer.random_state)

Expected result

None should be printed.

Actual result

A fixed seed of 0 is printed.

Traceback (if an exception is raised)

No response

Software versions

scikit-fda version: 0.9.2.dev0

Additional context

No response