RFC: Don't apply the compute profile when updating the host

Yop, we could remove the reference and use the values from the profile only when the host is created. We’ll update the documentation to explain that it’s used only for creating hosts. We can add tooltips to the form and disable compute profiles on host edit. That could be, let’s say, follow-up phase two.

Now, I need to find a fix that can be easily cherry-picked to (very) old releases with minimal changes; one customer is blocked on that.
The POC PR is a one-line change. While I agree it’s probably not the best PR in history, it does the job and fixes the problem with a one-line change.

@ekohl thoughts?