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, 3 deletions

diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 31ccbf23dc..d179a41884 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -340,8 +340,7 @@ class StateFilter:
 
 
 class StateGroupStorage:
-    """High level interface to fetching state for event.
-    """
+    """High level interface to fetching state for event."""
 
     def __init__(self, hs: "HomeServer", stores: "Databases"):
         self.stores = stores
@@ -400,7 +399,7 @@ class StateGroupStorage:
     async def get_state_groups(
         self, room_id: str, event_ids: Iterable[str]
     ) -> Dict[int, List[EventBase]]:
-        """ Get the state groups for the given list of event_ids
+        """Get the state groups for the given list of event_ids
 
         Args:
             room_id: ID of the room for these events.