This is a confusing, bad option, which was already disabled in groups,
and this removes it from personal libraries as well. People seem to be
using it mainly because they think annotations are locked into Zotero if
they don't, which is causing them to ask for this to be done
automatically on every edit, which we don't do because it would result
in constant file syncing and file conflicts [1].
We provide multiple export options for exporting PDFs with annotations,
and people can use those when sharing a file with people who don't use
Zotero. Otherwise, if storing annotations in the file is a priority,
they can use an external reader that's not designed to be tightly
integrated into Zotero.
(As a rare hack, it's of course also possible to export the PDF with
annotations, replace the original file, and import the annotations.)
[1] https://www.zotero.org/support/kb/annotations_in_database
e0097df068