👈 Launch a Binder on branch fcollonval/jupyter_server_ydoc/309-211-shows-jupyterlab-compatibility-warning-with-jupyterlab-42

On Binder build, the result of jupyter labextension list is

+ jupyter labextension list
JupyterLab v4.2.1
/srv/conda/envs/notebook/share/jupyter/labextensions
        jupyter-offlinenotebook v0.2.2 enabled  X
        jupyterlab_pygments v0.3.0 enabled OK (python, jupyterlab_pygments)
        @jupyter-widgets/jupyterlab-manager v5.0.10 enabled OK (python, jupyterlab_widgets)
        @jupyter-server/resource-usage v1.0.2 enabled OK (python, jupyter-resource-usage)
        @jupyter/collaboration-extension v2.1.1 enabled OK (python, jupyter_collaboration)


   The following extensions may be outdated or specify dependencies that are incompatible with the current version of jupyterlab:
        jupyter-offlinenotebook
        
   If you are a user, check if an update is available for these packages.
   If you are a developer, re-run with `--verbose` flag for more details.


Disabled extensions:
    @jupyterlab/filebrowser-extension:defaultFileBrowser

Failures seem to be caused by the latest release of AnyIO. In this PR, AnyIO now emits a ResourceWarning on unclosed memory object streams. So we should either explicitly close memory object streams (best) or ignore this warning in tests.

This is happening in pycrdt-websocket.
Another (temporary) option would be to pin anyio <4.4.0.

Failures seem to be caused by the latest release of AnyIO. In this PR, AnyIO now emits a ResourceWarning on unclosed memory object streams. So we should either explicitly close memory object streams (best) or ignore this warning in tests.

Thanks for highlighting the source of the error. I add the new warning to the ignore list of pytest in 4a311c7.

Thanks. I guess we should update the screenshots in the UI tests, as we did in 3.x?