Previously the controllers would proceed with additional creates,
updates, or deletes if 1 failed. That could potentially result in
scenarios where an EndpointSlice create or update failing while a delete
worked. This updates the logic so that removals will not happen if
additions fail.
This mirrors an earlier fix to the EndpointSlice controller. I'll make a
follow up PR to move this component to a shared package, but that seems
beyond the scope of a bug fix PR.
