Ros Noetic python3 - rqt cannot find plugins

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I am doing the tutorials and when I run rqt_graph node this occurs:

rosrun rqt_graph rqt_graph

Error Message:

CompositePluginProvider.discover() could not discover plugins from provider "<class 'rqt_gui.rospkg_plugin_provider.RospkgPluginProvider'>":
Traceback (most recent call last):
  File "/opt/ros/noetic/lib/python3/dist-packages/qt_gui/composite_plugin_provider.py", line 57, in discover
    plugin_descriptors = plugin_provider.discover(discovery_data)
  File "/opt/ros/noetic/lib/python3/dist-packages/rqt_gui/ros_plugin_provider.py", line 67, in discover
    plugin_descriptors += self._parse_plugin_xml(package_name, plugin_xml)
  File "/opt/ros/noetic/lib/python3/dist-packages/rqt_gui/ros_plugin_provider.py", line 128, in _parse_plugin_xml
    for library_el in root.getiterator('library'):
AttributeError: 'ElementTree' object has no attribute 'getiterator'

CompositePluginProvider.discover() could not discover plugins from provider "<class 'qt_gui.recursive_plugin_provider.RecursivePluginProvider'>":
Traceback (most recent call last):
  File "/opt/ros/noetic/lib/python3/dist-packages/qt_gui/composite_plugin_provider.py", line 57, in discover
    plugin_descriptors = plugin_provider.discover(discovery_data)
  File "/opt/ros/noetic/lib/python3/dist-packages/qt_gui/recursive_plugin_provider.py", line 53, in discover
    plugin_descriptors = self._plugin_provider.discover(discovery_data)
  File "/opt/ros/noetic/lib/python3/dist-packages/rqt_gui/ros_plugin_provider.py", line 67, in discover
    plugin_descriptors += self._parse_plugin_xml(package_name, plugin_xml)
  File "/opt/ros/noetic/lib/python3/dist-packages/rqt_gui/ros_plugin_provider.py", line 128, in _parse_plugin_xml
    for library_el in root.getiterator('library'):
AttributeError: 'ElementTree' object has no attribute 'getiterator'

CompositePluginProvider.discover() could not discover plugins from provider "<class 'qt_gui.recursive_plugin_provider.RecursivePluginProvider'>":
Traceback (most recent call last):
  File "/opt/ros/noetic/lib/python3/dist-packages/qt_gui/composite_plugin_provider.py", line 57, in discover
    plugin_descriptors = plugin_provider.discover(discovery_data)
  File "/opt/ros/noetic/lib/python3/dist-packages/qt_gui/recursive_plugin_provider.py", line 53, in discover
    plugin_descriptors = self._plugin_provider.discover(discovery_data)
  File "/opt/ros/noetic/lib/python3/dist-packages/rqt_gui/ros_plugin_provider.py", line 67, in discover
    plugin_descriptors += self._parse_plugin_xml(package_name, plugin_xml)
  File "/opt/ros/noetic/lib/python3/dist-packages/rqt_gui/ros_plugin_provider.py", line 128, in _parse_plugin_xml
    for library_el in root.getiterator('library'):
AttributeError: 'ElementTree' object has no attribute 'getiterator'

**qt_gui_main() found no plugin matching "rqt_graph.ros_graph.RosGraph"
try passing the option "--force-discover"**

Initially, it couldn't find PySide2 and PyQt5 which I installed via pip3 install.

When running in the terminal:

rqt_graph

there is no problem