MigrateCatalogInventoryNotifyStockQuantityData patch crashes when there is more then one stock in cataloginventory_stock

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### Preconditions (*)
1. Seen on Magento OS 2.4.6-p2 with MSI modules at version 1.2.6-p2

### Steps to reproduce (*)
1. We have a client with this super old Magento shop on version 2.2.3 that we are finally upgrading to 2.4.6-p2
2. This old shop has a module Magestore_Webpos that years ago created a second stock in the `cataloginventory_stock` table, and we also have a whole bunch of entries in the `cataloginventory_stock_item` table that references that second stock (id: 2)
3. When we upgrade this shop to Magento 2.4.6-p2 and enable the MSI modules, then running `bin/magento setup:upgrade` results in the following error:
```
...
layout: 1
block_html: 1
full_page: 1
Unable to apply data patch Magento\InventoryLowQuantityNotification\Setup\Patch\Data\MigrateCatalogInventoryNotifyStockQuantityData for module Magento_InventoryLowQuantityNotification. Original exception message: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'default-KB001' for key 'PRIMARY', query was: INSERT INTO `inventory_low_stock_notification_configuration` (`source_code`, `sku`, `notify_stock_qty`) SELECT `source_item`.`source_code`, `source_item`.`sku`, `stock_item`.`notify_stock_qty` FROM `cataloginventory_stock_item` AS `stock_item`
INNER JOIN `catalog_product_entity` AS `product` ON product.entity_id = stock_item.product_id
INNER JOIN `inventory_source_item` AS `source_item` ON source_item.sku = product.sku WHERE (stock_item.use_config_notify_stock_qty = 0) AND (source_item.source_code = 'default')
```

Running the SELECT part of the query results in:
```sql
mysql> SELECT `source_item`.`source_code`, `source_item`.`sku`, `stock_item`.`notify_stock_qty` FROM `cataloginventory_stock_item` AS `stock_item`
INNER JOIN `catalog_product_entity` AS `product` ON product.entity_id = stock_item.product_id
INNER JOIN `inventory_source_item` AS `source_item` ON source_item.sku = product.sku WHERE (stock_item.use_config_notify_stock_qty = 0) AND (source_item.source_code = 'default')
+-------------+-------+------------------+
| source_code | sku | notify_stock_qty |
+-------------+-------+------------------+
| default | KB001 | 0.0000 |
| default | KB001 | 0.0000 |
+-------------+-------+------------------+
2 rows in set (0.00 sec)
```

And indeed, there are 2 rows in `cataloginventory_stock_item` that correspond with this SKU (entity_id: 9158)
```sql
mysql> SELECT item_id, product_id, stock_id, use_config_notify_stock_qty FROM cataloginventory_stock_item WHERE product_id = '9158';
+---------+------------+----------+-----------------------------+
| item_id | product_id | stock_id | use_config_notify_stock_qty |
+---------+------------+----------+-----------------------------+
| 9158 | 9158 | 1 | 0 |
| 18830 | 9158 | 2 | 0 |
+---------+------------+----------+-----------------------------+
2 rows in set (0.00 sec)
```

So it sounds like this `MigrateCatalogInventoryNotifyStockQuantityData` patch can't deal with databases that have more then a single stock before MSI got installed.

### Expected result (*)
1. No errors

### Actual result (*)
1. See above

Start with Magento\InventoryLowQuantityNotification\Setup\Patch\Data\MigrateCatalogInventoryNotifyStockQuantityData and inspect the INSERT query against cataloginventory_stock_item, using the duplicate rows and setup:upgrade reproduction described here. Done means an installation with multiple legacy stocks completes without the duplicate-key error and the migration behavior is covered by appropriate tests.

Written by the indexing model from the issue text.