Issue:
---
Concurrent qty update might cause issue.

Steps to reproduce:
---
1- We need a DB with too many products. Also it might not be easy to reproduce the issue locally. Try runbot.
2- Create a SO.
3- On SOL creation, click on Catalog.
4- Copy the number 100 and click on catalog records fast and paste the number rapidly. Repeat this for all records of the page.
5- Go back to SO. You might find some lines with qty = 1.

Cause:
---
This is a concurrency issue. In the faulty cases, `update_order_line_info` setting quantity to 1, takes a few seconds to resolve, while the update setting quantity to 100 resolves faster (around 200ms). This cause the SOL final quantity set to 1.

As an example you could see two `update_order_line_info` requests for the same `product_id`, first one setting quantity to 1 and second one to 100, in which first one resolves faster.

<img width="912" height="316" alt="image" src="https://github.com/user-attachments/assets/219d2d10-32bf-490f-9f2c-a6229d60b991" />

<img width="927" height="328" alt="image" src="https://github.com/user-attachments/assets/1f0bddaf-e7d0-4311-b458-4416d77562c6" />

Fix:
---
We can chain RPC calls to ensure that each request is completed before starting the next one.

opw-5861412

Forward-Port-Of: odoo/odoo#250104

**Issue**:
The computation of cogs value, in AVCO (or FIFO) setup with kit of several component leads to traceback

**Steps to reproduce**:
- Create a kit product with 2 components: 
    - Inventory tracking enabled 
    - Use a category configured with AVCO and Perpetual (at invoicing) valuation
- Create a SO for the kit product and confirm it
- Go to the associated delivery and validate it
- Create and post the invoice on the so -> A traceback occurs

**Cause**:
In `_get_cogs_price_unit`, the code accesses `self.product_id.cost_method` assuming a singleton: https://github.com/odoo/odoo/blob/5d2e4b0f3fa8cdf2a977db05c7c2565b06ca2513/addons/stock_account/models/stock_move.py#L245 but `self.product_id` can be a multi-recordset when the sale line corresponds to a kit with multiple components https://github.com/odoo/odoo/blob/5d2e4b0f3fa8cdf2a977db05c7c2565b06ca2513/addons/stock_account/models/account_move_line.py#L67-L68 https://github.com/odoo/odoo/blob/5d2e4b0f3fa8cdf2a977db05c7c2565b06ca2513/addons/sale_stock/models/account_move.py#L155-L156

which causes the traceback.

**solution**
The solution has been inspired by this:
https://github.com/odoo/odoo/blob/008e69e8215fecc1f3fe45a36189592577cdc593/addons/stock_account/models/stock_move.py#L225-L228

opw-5880383

Forward-Port-Of: odoo/odoo#247775

## Issue
In the Point of Sale, when selling a product tracked by unique serial number with a quantity greater than one, no warning are displayed to the displayed as long as one serial number is given.

## Steps to reproduce
1. Install Point of Sale (`point_of_sale`)
2. In Settings, enable *Lots & Serial Numbers*
3. Create a PoS product P
    - Tracked *By Unique Serial Number*
    - Update its quantity and create a few serial numbers
4. In the Point of Sale, select product P and set a serial number, then update the quantity to 2.
5. **The _Valid product lot_ icon next to the product is still green. We can also go to the payment screen without any warning, even though only one serial number was selected for two products.**

## Cause
The color and name of the icon displayed next to the serial tracked product is decided here:

https://github.com/odoo/odoo/blob/3d787e1b7c2ab471694849a04bdf2d3a5ff7e515/addons/point_of_sale/static/src/app/screens/product_screen/order_summary/order_summary.xml#L9-L14

The `PosOrderLine.hasValidProductLot` is defined here:

https://github.com/odoo/odoo/blob/3d787e1b7c2ab471694849a04bdf2d3a5ff7e515/addons/point_of_sale/static/src/app/models/pos_order_line.js#L333-L341

The very first condition of this method makes the icon green as long as one serial number is selected.

opw-5486210

Forward-Port-Of: odoo/odoo#246930