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

1 files changed, 2 insertions, 4 deletions

diff --git a/tests/replication/test_client_reader_shard.py b/tests/replication/test_client_reader_shard.py
index 4608b65a0c..5da1d5dc4d 100644
--- a/tests/replication/test_client_reader_shard.py
+++ b/tests/replication/test_client_reader_shard.py
@@ -35,8 +35,7 @@ class ClientReaderTestCase(BaseMultiWorkerStreamTestCase):
         return config
 
     def test_register_single_worker(self):
-        """Test that registration works when using a single client reader worker.
-        """
+        """Test that registration works when using a single client reader worker."""
         worker_hs = self.make_worker_hs("synapse.app.client_reader")
         site = self._hs_to_site[worker_hs]
 
@@ -66,8 +65,7 @@ class ClientReaderTestCase(BaseMultiWorkerStreamTestCase):
         self.assertEqual(channel_2.json_body["user_id"], "@user:test")
 
     def test_register_multi_worker(self):
-        """Test that registration works when using multiple client reader workers.
-        """
+        """Test that registration works when using multiple client reader workers."""
         worker_hs_1 = self.make_worker_hs("synapse.app.client_reader")
         worker_hs_2 = self.make_worker_hs("synapse.app.client_reader")