test-api: Make desdemona consenting to private data export.

Fixes CI - it was failing due to the API test for organization exports,
which was returning an error due to there being no Organization Owners
with consent to private data export.

tools/test-api

@@ -37,6 +37,7 @@ with test_server_running(
         do_deactivate_realm,
         do_reactivate_realm,
     )
+    from zerver.actions.user_settings import do_change_user_setting
     from zerver.actions.users import change_user_is_active
     from zerver.lib.test_helpers import reset_email_visibility_to_everyone_in_zulip_realm
     from zerver.models.groups import NamedUserGroup, SystemGroups
@@ -87,6 +88,8 @@ with test_server_running(
     realm = get_realm("zulip")
     user = get_user(email, realm)
 
+    do_change_user_setting(user, "allow_private_data_export", True, acting_user=user)
+
     api_key = user.api_key
     site = "http://zulip.zulipdev.com:9981"
     owner_client = Client(