[REV] sale_margin: revert f5310d21c4

With the previous commit fixing the forced purchase_price recomputation
on all lines caused by the dependencies added by sale_stock_margin,
we can now safely allow manual edition of the cost.

closes odoo/odoo#107909

X-original-commit: 9c51daaa58c403778861ec484e0493698bacbc92
Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>

addons/sale_margin/models/sale_order_line.py

@@ -14,7 +14,7 @@ class SaleOrderLine(models.Model):
         "Margin (%)", compute='_compute_margin', store=True, groups="base.group_user", precompute=True)
     purchase_price = fields.Float(
         string="Cost", compute="_compute_purchase_price",
-        digits='Product Price', store=True, precompute=True,
+        digits='Product Price', store=True, readonly=False, precompute=True,
         groups="base.group_user")
 
     @api.depends('product_id', 'company_id', 'currency_id', 'product_uom')