python: reformat with black-23.7.0-2.fc39.noarch

The base image for the "check-tree" test got bumped to Fedora 39.  This
brings a new python-black version (23.7.0 vs. 22.8.0) and requires
reformatting.

Maybe we should stick to 22.8.0, via `pip install`. But it seems better
to just follow the latest black version (the one from current Fedora).

So do the reformatting instead.

https://black.readthedocs.io/en/stable/change_log.html#id38

examples/python/gi/nm-add-connection2.py

@@ -49,7 +49,6 @@ def die(msg, print_usage=False):
 
 
 def main():
-
     main_loop = GLib.MainLoop()
 
     nm_client = NM.Client.new(None)