qt4 is no longer supported crash

[ossadtchi]

General information
OS: ( MacOS)
NFB Lab version: (0.1.0, 0.1.1, ...)

Bug description
just start pynfb and
(base) Carloss-Air:~ Leo$ pynfb
/usr/local/lib/python3.9/site-packages
Traceback (most recent call last):
File "/usr/local/bin/pynfb", line 5, in
from pynfb.main import main
File "/usr/local/lib/python3.9/site-packages/pynfb/main.py", line 15, in
from pynfb.settings_widget import SettingsWidget
File "/usr/local/lib/python3.9/site-packages/pynfb/settings_widget/init.py", line 6, in
from pynfb.experiment import Experiment
File "/usr/local/lib/python3.9/site-packages/pynfb/experiment.py", line 21, in
from .protocols import BaselineProtocol, FeedbackProtocol, ThresholdBlinkFeedbackProtocol, VideoProtocol
File "/usr/local/lib/python3.9/site-packages/pynfb/protocols/init.py", line 18, in
from ..protocols.user_inputs import SelectSSDFilterWidget
File "/usr/local/lib/python3.9/site-packages/pynfb/protocols/user_inputs.py", line 6, in
from ..protocols.ssd import TopomapSelector
File "/usr/local/lib/python3.9/site-packages/pynfb/protocols/ssd/init.py", line 1, in
from .topomap_selector import TopomapSelector
File "/usr/local/lib/python3.9/site-packages/pynfb/protocols/ssd/topomap_selector.py", line 4, in
from ...protocols.ssd.topomap_canvas import TopographicMapCanvas
File "/usr/local/lib/python3.9/site-packages/pynfb/protocols/ssd/topomap_canvas.py", line 5, in
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
ModuleNotFoundError: No module named 'matplotlib.backends.backend_qt4agg'