[FIX] purchase_mrp: dependency

- Create 3 products: A, A1 and A2
- Create a BOM kit: A is a kit containing A1 and A2
- Purchase 1 unit of A
- Receive the quantities

The Received Quantity is set to 2 instead of 1.

This happens because `_update_received_qty` is not called as expected.
Indeed, `purchase_mrp` must depend on `purchase_stock` since it
overrides `_update_received_qty`.

opw-2166749

closes odoo/odoo#43097

Related: odoo/enterprise#7712
Signed-off-by: Christophe Simonis <chs@odoo.com>