[FIX] purchase: currency of supplierinfo

Set the currency of the supplier info according to the currency set on
the partner.

opw-1951314

closes odoo/odoo#32098

Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

addons/purchase/models/product.py

@@ -91,3 +91,11 @@ class ProductCategory(models.Model):
         'account.account', string="Price Difference Account",
         company_dependent=True,
         help="This account will be used to value price difference between purchase price and accounting cost.")
+
+
+class SupplierInfo(models.Model):
+    _inherit = "product.supplierinfo"
+
+    @api.onchange('name')
+    def _onchange_partner_id(self):
+        self.currency_id = self.name.property_purchase_currency_id or self.env.user.company_id.currency_id