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, 6 insertions, 11 deletions

diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index 9840a9d55b..43b1f1e94b 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -58,7 +58,7 @@ def register_sighup(func, *args, **kwargs):
 
 
 def start_worker_reactor(appname, config, run_command=reactor.run):
-    """ Run the reactor in the main process
+    """Run the reactor in the main process
 
     Daemonizes if necessary, and then configures some resources, before starting
     the reactor. Pulls configuration from the 'worker' settings in 'config'.
@@ -93,7 +93,7 @@ def start_reactor(
     logger,
     run_command=reactor.run,
 ):
-    """ Run the reactor in the main process
+    """Run the reactor in the main process
 
     Daemonizes if necessary, and then configures some resources, before starting
     the reactor
@@ -313,9 +313,7 @@ async def start(hs: "synapse.server.HomeServer", listeners: Iterable[ListenerCon
     refresh_certificate(hs)
 
     # Start the tracer
-    synapse.logging.opentracing.init_tracer(  # type: ignore[attr-defined] # noqa
-        hs
-    )
+    synapse.logging.opentracing.init_tracer(hs)  # type: ignore[attr-defined] # noqa
 
     # It is now safe to start your Synapse.
     hs.start_listening(listeners)
@@ -370,8 +368,7 @@ def setup_sentry(hs):
 
 
 def setup_sdnotify(hs):
-    """Adds process state hooks to tell systemd what we are up to.
-    """
+    """Adds process state hooks to tell systemd what we are up to."""
 
     # Tell systemd our state, if we're using it. This will silently fail if
     # we're not using systemd.
@@ -405,8 +402,7 @@ def install_dns_limiter(reactor, max_dns_requests_in_flight=100):
 
 
 class _LimitedHostnameResolver:
-    """Wraps a IHostnameResolver, limiting the number of in-flight DNS lookups.
-    """
+    """Wraps a IHostnameResolver, limiting the number of in-flight DNS lookups."""
 
     def __init__(self, resolver, max_dns_requests_in_flight):
         self._resolver = resolver
diff --git a/synapse/app/generic_worker.py b/synapse/app/generic_worker.py
index 516f2464b4..6526acb2f2 100644
--- a/synapse/app/generic_worker.py
+++ b/synapse/app/generic_worker.py
@@ -421,8 +421,7 @@ class GenericWorkerPresence(BasePresenceHandler):
         ]
 
     async def set_state(self, target_user, state, ignore_status_msg=False):
-        """Set the presence state of the user.
-        """
+        """Set the presence state of the user."""
         presence = state["presence"]
 
         valid_presence = (