🍒 Summary

As mentioned here, the Machine Learning group disappeared from the o11y stateful side navigation. It turns out that this PR automatically disabled the security plugin, and in consequence the ML landing page is not accessible from the o11y plugin. As it is not available, the side nav automatically removed the whole “Machine learning” group.

Proposal

1. we should move that landing page inside the maching learning plugin (x-pack/ml) and
2. declare the deeplink in the ml plugin (not security)

cc @sebelga @semd