Transaction write fails lead to transactions not being rolled back synchronously

When performing a COMMIT operation, if the underlying writes from the delta-table trigger a failure in gocbcore's transactions, query rolls back the transaction but does not wait for the rollback to complete before returning a response to the caller. This is triggering a race condition issue with the transactions testing suite. This can also lead to transactions failing due to write-write conflicts during retries, as the later attempts may end up conflicting with the earlier attempt that has not finished rolling back.