that seems not to be the case [and it also used to work before the update]:
[root@hub ~]# locate matplotlib-inline
[root@hub ~]# locate matplotlib_inline
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline/init.py
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline/pycache
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline/backend_inline.py
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline/config.py
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline/pycache/init.cpython-39.pyc
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline/pycache/backend_inline.cpython-39.pyc
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline/pycache/config.cpython-39.pyc
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info/INSTALLER
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info/LICENSE
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info/METADATA
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info/RECORD
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info/WHEEL
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info/top_level.txt
[root@hub ~]# dnf list installed | grep matplot
[root@hub ~]# locate entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/Babel-2.15.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/Mako-1.3.5.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/Send2Trash-1.8.3.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/alembic-1.13.1.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/anyio-4.4.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/ase-3.23.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/certipy-0.1.3.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/cffi-1.16.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/charset_normalizer-3.3.2.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/fonttools-4.53.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/httpx-0.27.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/ipython-8.18.1.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jinja2-3.1.4.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/json5-0.9.25.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jsonschema-4.22.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jupyter_client-8.6.2.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jupyter_core-5.7.2.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jupyter_events-0.10.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jupyter_lsp-2.2.5.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jupyter_server-2.14.1.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jupyterhub-5.0.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/jupyterlab-4.2.1.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/matplotlib_inline-0.1.7.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/nbclient-0.10.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/nbconvert-7.16.4.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/nbformat-5.10.4.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/numpy-1.26.4.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/pip-24.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/pygments-2.18.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/setuptools-53.0.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/websocket_client-1.8.0.dist-info/entry_points.txt
/opt/jupyterhub/lib/python3.9/site-packages/wheel-0.43.0.dist-info/entry_points.txt
/usr/lib/python3.9/site-packages/chardet-4.0.0.dist-info/entry_points.txt
/usr/lib/python3.9/site-packages/conda-4.14.0-py3.9.egg-info/entry_points.txt
/usr/lib/python3.9/site-packages/distro-1.5.0-py3.9.egg-info/entry_points.txt
/usr/lib/python3.9/site-packages/py_cpuinfo-8.0.0-py3.9.egg-info/entry_points.txt
/usr/lib/python3.9/site-packages/setuptools-53.0.0.dist-info/entry_points.txt
/usr/lib/python3.9/site-packages/tqdm-4.65.0.dist-info/entry_points.txt
/usr/lib64/python3.9/site-packages/cffi-1.14.5-py3.9.egg-info/entry_points.txt
/usr/lib64/python3.9/site-packages/conda_package_handling-1.7.3-py3.9.egg-info/entry_points.txt
[root@hub ~]#
the problem only occurs when loading matplotlib in JupyterLab, not from the bash terminal using the venv.
To be even more precise:
[root@hub ~]# find / -type f -name entry_points.txt -exec grep -i inline ‘{}’ ‘;’
inline = matplotlib_inline.backend_inline
[root@hub ~]#
So my conclusion is that the file is read twice somehow when running through a JupyterLab ipython console session?