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

synmark/__main__.py

@@ -96,5 +96,6 @@ if __name__ == "__main__":
             runner.args.loops = orig_loops
             loops = "auto"
         runner.bench_time_func(
-            suite.__name__ + "_" + str(loops), make_test(suite.main),
+            suite.__name__ + "_" + str(loops),
+            make_test(suite.main),
         )

synmark/suites/logging.py

@@ -98,7 +98,9 @@ async def main(reactor, loops):
 
     logger = logging.getLogger("synapse.logging.test_terse_json")
     _setup_stdlib_logging(
-        hs_config, log_config, logBeginner=beginner,
+        hs_config,
+        log_config,
+        logBeginner=beginner,
     )
 
     # Wait for it to connect...