IsSalableOptionPlugin afterGetUsedProducts is not getting called

### Preconditions (*)

1. 2.4.4-p1

### Steps to reproduce (*)

1. The plugin is not added for GQL
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2. It should be added to `https://github.com/magento/inventory/blob/develop/InventoryConfigurableProduct/etc/graphql/di.xml`

### Expected result (*)

1. Plugin should be called while doing GQL query for a configurable product

### Actual result (*)

1. Plugin is not called

Start with InventoryConfigurableProduct/etc/graphql/di.xml and the IsSalableOptionPlugin configuration shown in the report. Reproduce the configurable-product GraphQL query, trace whether afterGetUsedProducts is reached, and verify that the plugin is called during that query.

Written by the indexing model from the issue text.