[4.2.x] Refs #33476 -- Applied Black's 2023 stable style.

Black 23.1.0 is released which, as the first release of the year,
introduces the 2023 stable style. This incorporates most of last year's
preview style.

https://github.com/psf/black/releases/tag/23.1.0

Backport of 097e3a70c1 from main

tests/sessions_tests/tests.py

@@ -390,7 +390,6 @@ class SessionTestsMixin:
 
 
 class DatabaseSessionTests(SessionTestsMixin, TestCase):
-
     backend = DatabaseSession
     session_engine = "django.contrib.sessions.backends.db"
 
@@ -501,7 +500,6 @@ class CustomDatabaseSessionTests(DatabaseSessionTests):
 
 
 class CacheDBSessionTests(SessionTestsMixin, TestCase):
-
     backend = CacheDBSession
 
     def test_exists_searches_cache_first(self):
@@ -528,7 +526,6 @@ class CacheDBSessionWithTimeZoneTests(CacheDBSessionTests):
 
 
 class FileSessionTests(SessionTestsMixin, SimpleTestCase):
-
     backend = FileSession
 
     def setUp(self):
@@ -624,7 +621,6 @@ class FileSessionPathLibTests(FileSessionTests):
 
 
 class CacheSessionTests(SessionTestsMixin, SimpleTestCase):
-
     backend = CacheSession
 
     # Some backends might issue a warning
@@ -880,7 +876,6 @@ class SessionMiddlewareTests(TestCase):
 
 
 class CookieSessionTests(SessionTestsMixin, SimpleTestCase):
-
     backend = CookieSession
 
     def test_save(self):