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, 4 insertions, 8 deletions

diff --git a/synapse/groups/attestations.py b/synapse/groups/attestations.py
index 41cf07cc88..db69bb7c06 100644
--- a/synapse/groups/attestations.py
+++ b/synapse/groups/attestations.py
@@ -61,8 +61,7 @@ UPDATE_ATTESTATION_TIME_MS = 1 * 24 * 60 * 60 * 1000
 
 
 class GroupAttestationSigning:
-    """Creates and verifies group attestations.
-    """
+    """Creates and verifies group attestations."""
 
     def __init__(self, hs):
         self.keyring = hs.get_keyring()
@@ -125,8 +124,7 @@ class GroupAttestationSigning:
 
 
 class GroupAttestionRenewer:
-    """Responsible for sending and receiving attestation updates.
-    """
+    """Responsible for sending and receiving attestation updates."""
 
     def __init__(self, hs):
         self.clock = hs.get_clock()
@@ -142,8 +140,7 @@ class GroupAttestionRenewer:
             )
 
     async def on_renew_attestation(self, group_id, user_id, content):
-        """When a remote updates an attestation
-        """
+        """When a remote updates an attestation"""
         attestation = content["attestation"]
 
         if not self.is_mine_id(group_id) and not self.is_mine_id(user_id):
@@ -161,8 +158,7 @@ class GroupAttestionRenewer:
         return run_as_background_process("renew_attestations", self._renew_attestations)
 
     async def _renew_attestations(self):
-        """Called periodically to check if we need to update any of our attestations
-        """
+        """Called periodically to check if we need to update any of our attestations"""
 
         now = self.clock.time_msec()