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, 61 insertions, 14 deletions

diff --git a/tests/state/test_v2.py b/tests/state/test_v2.py
index 77c72834f2..66e3cafe8e 100644
--- a/tests/state/test_v2.py
+++ b/tests/state/test_v2.py
@@ -382,8 +382,7 @@ class StateTestCase(unittest.TestCase):
         self.do_check(events, edges, expected_state_ids)
 
     def test_mainline_sort(self):
-        """Tests that the mainline ordering works correctly.
-        """
+        """Tests that the mainline ordering works correctly."""
 
         events = [
             FakeEvent(
@@ -660,15 +659,27 @@ class AuthChainDifferenceTestCase(unittest.TestCase):
         #           C -|-> B -> A
 
         a = FakeEvent(
-            id="A", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="A",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([], [])
 
         b = FakeEvent(
-            id="B", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="B",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([a.event_id], [])
 
         c = FakeEvent(
-            id="C", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="C",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([b.event_id], [])
 
         persisted_events = {a.event_id: a, b.event_id: b}
@@ -694,19 +705,35 @@ class AuthChainDifferenceTestCase(unittest.TestCase):
         #      D -> C -|-> B -> A
 
         a = FakeEvent(
-            id="A", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="A",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([], [])
 
         b = FakeEvent(
-            id="B", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="B",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([a.event_id], [])
 
         c = FakeEvent(
-            id="C", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="C",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([b.event_id], [])
 
         d = FakeEvent(
-            id="D", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="D",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([c.event_id], [])
 
         persisted_events = {a.event_id: a, b.event_id: b}
@@ -737,23 +764,43 @@ class AuthChainDifferenceTestCase(unittest.TestCase):
         #              |
 
         a = FakeEvent(
-            id="A", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="A",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([], [])
 
         b = FakeEvent(
-            id="B", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="B",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([a.event_id], [])
 
         c = FakeEvent(
-            id="C", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="C",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([b.event_id], [])
 
         d = FakeEvent(
-            id="D", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="D",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([c.event_id], [])
 
         e = FakeEvent(
-            id="E", sender=ALICE, type=EventTypes.Member, state_key="", content={},
+            id="E",
+            sender=ALICE,
+            type=EventTypes.Member,
+            state_key="",
+            content={},
         ).to_event([c.event_id, b.event_id], [])
 
         persisted_events = {a.event_id: a, b.event_id: b}