Can't pickle class 'plone.app.upgrade.bbb.ITinyMCE'

I had deleted portal_tinymce in the py2 to py3 migration steps in the fixes for https://community.plone.org/t/upgrade-to-5-2-failing-with-iatcttool-has-no-attribute-iro

How would I clean up its registration as a utility in 5.2?