Upgrade black version (#7089)

stdlib/time.pyi

@@ -99,6 +99,7 @@ if sys.version_info >= (3, 7):
     if sys.platform != "win32":
         def clock_gettime_ns(clock_id: int) -> int: ...
         def clock_settime_ns(clock_id: int, time: int) -> int: ...
+
     def monotonic_ns() -> int: ...
     def perf_counter_ns() -> int: ...
     def process_time_ns() -> int: ...