[FIX] mrp: incorrect computation of the on-hand qty of a kit

ref : https://github.com/odoo/odoo/commit/d3b482b1d6c9f19ff428b3918c0e09b11c87c873


more then 3 upgrade requests failed.

closes odoo/odoo#105627

Signed-off-by: Djamel Touati (otd) <otd@odoo.com>