[FIX] stock: _compute_qty_order should not take environement context

savepoint do a flush that throw the current context and then recompute
the stored field (with a random matching context from the transaction).
In the case of qty_to_order, it will call qty_forecast and then
_compute_quantities on product.product.

Currently it will call _compute_quantities with a mix of self.env.context
(from the transaction) and a context generated from the orderpoint (with
deterministic data). But sometimes in the context took from the
transaction it could remain some other key used by _compute_quantities
(e.g. warehouse_id). Since qty_to_order doens't depends from context
it should not use self.env.context and only use the deterministic
context from the stock.orderpoint

closes odoo/odoo#100150

X-original-commit: 79694a88978ebc1213d6ba0ac0dcc59640f16d04
Signed-off-by: William Henrotin (whe) <whe@odoo.com>

addons/stock/models/stock_orderpoint.py

@@ -249,7 +249,7 @@ class StockWarehouseOrderpoint(models.Model):
                 orderpoint.qty_forecast = False
                 continue
             orderpoint_context = orderpoint._get_product_context()
-            product_context = frozendict({**self.env.context, **orderpoint_context})
+            product_context = frozendict({**orderpoint_context})
             orderpoints_contexts[product_context] |= orderpoint
         for orderpoint_context, orderpoints_by_context in orderpoints_contexts.items():
             products_qty = {