Avoid timeout when updating large number of references

As a reminder - please set the "Assigned" field back to "Unassigned" once you are finished with your changes so others can know you're finished.

Pretty sure that this is related to 🐛 Timeouts when merging two taxonomies with a lot of content Active

FYI I created a Drupal 7 Issue for this too. I don't expect much traction, but I found this issue is also a challenge there too, and some sites may want to consolidate data before they migrate using the D7 version of this module.