Reviews by Product: list items have incorrect aria-label

[Aljullu]

Blocks #11975.

To reproduce

1. Create a post or page.
2. Add the Reviews by Product block.
3. Using the browser Inspector (F12), select one of the checkboxes.
4. Notice the value of the aria-label shows placeholder signs: %1$s and %2$2.
5. There is also an error in the console: TypeError: [sprintf] expecting number but found undefined.

Expected behavior

There should be no error and the aria-label value should show the product name and the number of reviews.