community/glances: add missing dep py3-defusedxml

Fixing the following error on launch of glances:

Traceback (most recent call last):
  File "/usr/bin/glances", line 33, in <module>
    sys.exit(load_entry_point('Glances==3.2.2', 'console_scripts', 'glances')())
  File "/usr/bin/glances", line 25, in importlib_load_entry_point
    return next(matches).load()
  File "/usr/lib/python3.9/importlib/metadata.py", line 77, in load
    module = import_module(match.group('module'))
  File "/usr/lib/python3.9/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 850, in exec_module
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
  File "/usr/lib/python3.9/site-packages/glances/__init__.py", line 46, in <module>
    from glances.main import GlancesMain
  File "/usr/lib/python3.9/site-packages/glances/main.py", line 27, in <module>
    from glances.compat import input, disable, enable
  File "/usr/lib/python3.9/site-packages/glances/compat.py", line 48, in <module>
    from defusedxml.xmlrpc import monkey_patch
ModuleNotFoundError: No module named 'defusedxml'

Ref https://github.com/nicolargo/glances/blob/v3.2.3/setup.py#L44