tests/e2e: Add delay and serialized rollback to saml e2e test (#18840)

* Add delay and serialized rollback to saml e2e test

* Apply suggestion from @BeryJu

Signed-off-by: Jens L. <jens@beryju.org>

* trigger build

---------

Signed-off-by: Jens L. <jens@beryju.org>
Co-authored-by: Jens L. <jens@goauthentik.io>

tests/e2e/test_provider_saml.py

@@ -687,3 +687,4 @@ class TestProviderSAML(SeleniumTestCase):
             [self.user.email],
             f"Claim 'upn' mismatch at {self.driver.current_url}: {snippet}",
         )
+        sleep(3)

tests/e2e/utils.py

@@ -163,6 +163,7 @@ class DockerTestCase(TestCase):
 class SeleniumTestCase(DockerTestCase, StaticLiveServerTestCase):
     """StaticLiveServerTestCase which automatically creates a Webdriver instance"""
 
+    serialized_rollback = True
     host = get_local_ip()
     wait_timeout: int
     user: User