obsoletion of alga results in dangling axioms

[cmungall]

In

• Proposal: obsolete 'alga' #1448.

We obsoleted "alga" but did not fix the algal bloom hierarchy that depends on it.

The immediate course of action is to delete the dangling axioms

When @hrshdhgd I will coordinate with him on ensuring this doesn't happen again. The java kgcl agent handled this request, it looks like it doesn't do a cascading delete as the OAK one does.