Ensure users have been created [ci drivers]

There are occasional test failures in nested-queries-test that is due
to the order of tests being ran and the presence (or absence of test
users. This commit just always ensures the users are there before the
test runs.

test/metabase/query_processor_test/nested_queries_test.clj

@@ -21,7 +21,7 @@
              [util :as tu]]
             [metabase.test.data
              [datasets :as datasets]
-             [users :refer [user->client]]]
+             [users :refer [create-users-if-needed! user->client]]]
             [toucan.db :as db]
             [toucan.util.test :as tt]))
 
@@ -487,6 +487,7 @@
   db)`."
   [f]
   (tt/with-temp Database [db {:details (:details (data/db)), :engine "h2"}]
+    (create-users-if-needed!)
     (f db)))
 
 (defn- save-card-via-API-with-native-source-query!