[FIX] project: remove unused field
[FIX] project: remove unused field

If `description` contains an image, the loading time of the kanban view
can be rather long. Since the field is not even used in the view, it can
be removed.

opw-1915193

closes odoo/odoo#29034
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo