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
`](80d6dc9783/docs/code_style.md)
 - Update `code_style.md` docs around installing black to use the correct version

synapse/storage/prepare_database.py

@@ -425,7 +425,10 @@ def _upgrade_existing_database(
             # We don't support using the same file name in the same delta version.
             raise PrepareDatabaseException(
                 "Found multiple delta files with the same name in v%d: %s"
-                % (v, duplicates,)
+                % (
+                    v,
+                    duplicates,
+                )
             )
 
         # We sort to ensure that we apply the delta files in a consistent
@@ -532,7 +535,8 @@ def _apply_module_schema_files(
         names_and_streams: the names and streams of schemas to be applied
     """
     cur.execute(
-        "SELECT file FROM applied_module_schemas WHERE module_name = ?", (modname,),
+        "SELECT file FROM applied_module_schemas WHERE module_name = ?",
+        (modname,),
     )
     applied_deltas = {d for d, in cur}
     for (name, stream) in names_and_streams: