all: Update Python formatting to latest Black version 21.12b0.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

extmod/uasyncio/event.py

@@ -57,6 +57,5 @@ try:
                 yield core._io_queue.queue_read(self)
             self._flag = 0
 
-
 except ImportError:
     pass

ports/stm32/make-stmconst.py

@@ -17,7 +17,6 @@ if platform.python_version_tuple()[0] == "2":
     def convert_bytes_to_str(b):
         return b
 
-
 elif platform.python_version_tuple()[0] == "3":
 
     def convert_bytes_to_str(b):

tests/extmod/utimeq1.py

@@ -17,7 +17,6 @@ if DEBUG:
     def dprint(*v):
         print(*v)
 
-
 else:
 
     def dprint(*v):

tools/pydfu.py

@@ -84,7 +84,6 @@ if "length" in getargspec(usb.util.get_string).args:
     def get_string(dev, index):
         return usb.util.get_string(dev, 255, index)
 
-
 else:
     # PyUSB 1.0.0.b2 dropped the length argument
     def get_string(dev, index):