Make pyright happy

Signed-off-by: Jose Luis Rivero <jrivero@osrfoundation.org>

Author: j-rivero

gzdev.py

@@ -26,6 +26,7 @@
 from docopt import docopt
 
 if __name__ == '__main__':
+    assert __doc__ is not None  # make pyright happy
     args = docopt(__doc__, version='gzdev-core 0.1.0', options_first=True)
     cmd = args['<command>']
     is_valid = {'ign-docker-env': True,