Many of the index builds in indexu.js succeed on the assumption that there are no documents in the collection. However, in the multi_stmt_txn_jscore_passthrough_with_migrations suite, we cannot predict the timeliness of the deletion of orphan documents from migrations. Thus, some of these index builds fail because they still view the orphan document. This is correct behavior since

https://jira.mongodb.org/browse/PM-2098 made it so broadcast deleteMany won't delete any unowned documents

and `validate` assumes every document has an index built on it, regardless of if it is owned or unowned.

We can address this by either allowing the error `16746` to be thrown at these index build assertions or we can disable the test indexu.js from the multi_stmt_txn_jscore_passthrough_with_migrations suite.

I think it's fine to disable the test from the suite. The test is definitely written under the assumption that there are no orphan documents.