Template Sync now uses the new (as of EE 3.5.0)
core_boothook to perform the sync. This fixes the incompatibility starting somewhere around EE 3.4.0 where models would throw errors on session hooks.
This does require EE 3.5.0 or newer since the
core_boothook does not exist prior to that — although having this version of Template Sync installed on older versions of EE 3 should not cause any errors or problems, it just means that no syncing will be performed.