before this commit: while changing subtypes of the project it was only propagating those subtypes to the task, whose parent_id is set. internal subtypes are not propagating in the task of a project. So, filter internal subtypes and concat them with the subtypes which have parent_id. after this commit: internal subtypes will also propagate to their tasks closes odoo/odoo#64767 X-original-commit: f29e9e5edbe08e1a356ceb7c2dbb2f60fb6d3ff5 X-original-pr: odoo/odoo#47336 Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>