Update hook eroneously adds title field to all "Full" displays with layout builder enabled

Problem/Motivation

After updating from 2.x to 3.0.1, a title block was added to all of my "Full" node displays using layout builder. This should not have happened and I'm not sure why it did happen. If I had to guess, it's because the displays had been set to use the title field, but the normal Manage Display was not emptied before enabling layout builder for the node type.

The only update hooks that were run were 9301 and 9302. It looks like it must've been 9301, but I'm really not sure.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes