update and bulkWrite command responses can now contain a writeConcernError field in more cases than before.
The writeConcernError field in the response is not new and its format is not changed by this PR. However, previously the writeConcernError field was not returned in some cases in which it is justified.
These cases were limited to update/bulkWrite queries on sharded collections that did not use the shard key. Here, if one of the shards returned a writeConcernError *and* another error happened (e.g. DocumentValidationFailed), then it was possible that the writeConcernError field was not returned.

Description of Linked Ticket

When enabling some tests that were previously commented out with a TODO SERVER-98461 comment above them, I found that some commands update / bulkWrite do not return the writeConcernError s as expected by the test.

These test errors are not related to findAndModify (and thus SERVER-98461), so we did not enable the failing assertions as part of SERVER-98461. But we should definitely follow this up and make sure that update / bulkWrite always return writeConcernError s as expected.