Remove anti-links to other personas.
The UIDs of all personas in
other_personas will be removed from this persona's anti-links set and the changes propagated to
If the global anti-link is set, this will not have any effect until the global anti-link is removed.
This method is safe to call multiple times concurrently (e.g. begin one asynchronous call, then begin another before the first has finished).
the personas to remove anti-links from this one
if setting the anti-links failed