Update black, and run auto formatting over the codebase (#9381)

 - Update black version to the latest
 - Run black auto formatting over the codebase
    - Run autoformatting according to [`docs/code_style.md
`](https://github.com/matrix-org/synapse/blob/80d6dc9783aa80886a133756028984dbf8920168/docs/code_style.md)
 - Update `code_style.md` docs around installing black to use the correct version

2 files changed, 22 insertions, 5 deletions

diff --git a/tests/api/test_auth.py b/tests/api/test_auth.py
index b1a8c58e1c..34f72ae795 100644
--- a/tests/api/test_auth.py
+++ b/tests/api/test_auth.py
@@ -276,7 +276,10 @@ class AuthTestCase(unittest.HomeserverTestCase):
             if token != tok:
                 return None
             return TokenLookupResult(
-                user_id=USER_ID, is_guest=False, token_id=1234, device_id="DEVICE",
+                user_id=USER_ID,
+                is_guest=False,
+                token_id=1234,
+                device_id="DEVICE",
             )
 
         self.store.get_user_by_access_token = get_user
diff --git a/tests/api/test_ratelimiting.py b/tests/api/test_ratelimiting.py
index fe504d0869..483418192c 100644
--- a/tests/api/test_ratelimiting.py
+++ b/tests/api/test_ratelimiting.py
@@ -43,7 +43,11 @@ class TestRatelimiter(unittest.TestCase):
 
     def test_allowed_appservice_ratelimited_via_can_requester_do_action(self):
         appservice = ApplicationService(
-            None, "example.com", id="foo", rate_limited=True, sender="@as:example.com",
+            None,
+            "example.com",
+            id="foo",
+            rate_limited=True,
+            sender="@as:example.com",
         )
         as_requester = create_requester("@user:example.com", app_service=appservice)
 
@@ -68,7 +72,11 @@ class TestRatelimiter(unittest.TestCase):
 
     def test_allowed_appservice_via_can_requester_do_action(self):
         appservice = ApplicationService(
-            None, "example.com", id="foo", rate_limited=False, sender="@as:example.com",
+            None,
+            "example.com",
+            id="foo",
+            rate_limited=False,
+            sender="@as:example.com",
         )
         as_requester = create_requester("@user:example.com", app_service=appservice)
 
@@ -113,12 +121,18 @@ class TestRatelimiter(unittest.TestCase):
         limiter = Ratelimiter(clock=None, rate_hz=0.1, burst_count=1)
 
         # First attempt should be allowed
-        allowed, time_allowed = limiter.can_do_action(("test_id",), _time_now_s=0,)
+        allowed, time_allowed = limiter.can_do_action(
+            ("test_id",),
+            _time_now_s=0,
+        )
         self.assertTrue(allowed)
         self.assertEqual(10.0, time_allowed)
 
         # Second attempt, 1s later, will fail
-        allowed, time_allowed = limiter.can_do_action(("test_id",), _time_now_s=1,)
+        allowed, time_allowed = limiter.can_do_action(
+            ("test_id",),
+            _time_now_s=1,
+        )
         self.assertFalse(allowed)
         self.assertEqual(10.0, time_allowed)