[FIX] stock: select seller date
[FIX] stock: select seller date

When the function '_select_seller' in stock warehouse is called, a
datetime is passed to it. But the method needs a date, so we modify it.

OPW-1930264

closes odoo/odoo#30563
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo